I? 


THE   NEW   KNOWLEDGE. 


The     New     SCIENCE     SERIES 

EDITED  BY   PROF.  ROBERT  KENNEDY   DUNCAN 

This  series  gives  a  general  view  of  the  new  work  in  science 
which  is  having  such  broad  and  unexpected  results.  These  results, 
as  in  the  case  of  radio-activity  and  the  theories  which  are  being  based 
upon  the  resolution  of  atoms,  researches  into  the  origin  of  life  and 
investigation  in  many  other  fields,  have  been  presented  either  in 
special  monographs  or  when  popularized  with  reference  to  their  more 
sensational  phases.  So  far  as  these  new  discoveries  are  concerned,  the 
work  of  popular  but  accurate  exposition  and  comprehensive  synthesis 
which  was  done  by  Huxley  and  others  for  a  past  generation  has  been 
very  largely  lacking,  and  the  demand  for  a  general  review  of  the  new 
work  of  science  will  it  is  hoped,  be  met  in  this  series.  The  con- 
tributors will  include  men  of  high  scientific  standing  in  this  country 
and  abroad  who  have  a  gift  of  expression  as  well  as  knowledge,  and  in 
the  preparation  of  these  books  the  advice  of  many  distinguished 
specialists  has  been  freely  drawn  upon. 

THE   NEW  KNOWLEDGE 

A  Popular  Account  of  the  New  Physics  and  the  New  Chemistry  in 
their  Relation  to  the  New  Theory  of  Matter. 

By   ROBERT  KENNEDY  DUNCAN,   Professor  of  Chemistry 
in  Washington  and  Jefferson  College. 

"Laymen  in  science,"  says  the  brilliant  author  of  this  remarkable 
presentation  of  new  science,  "are  usually  limited  to  pseudo-science  or 
else  to  technical  books."  His  own  book  requires  no  more  of  the 
reader  than  a  high-school  education  and  a  love  of  contemporary 
natural  knowledge.  Locked  up  in  this  new  knowledge  is  the  cause  of 
the  heat  of  the  sun,  together  with  the  nature  of  electricity,  the  evolution 
of  a  universe  and  the  birth  and  decay  of  matter.  There  are  possibly  a 
cure  for  tuberculosis,  light  without  heat,  a  demonstration  of  vast 
stores  of  energy  hitherto  unsuspected  and  a  whole  series  of  radiations 
from  matter  in  the  natural  state.  The  whole  field  opened  so  recently, 
ranging  from  the  atoms  of  the  elements,  corpuscles,  the  various  rays, 
radio-activity,  and  inter-atomic  energy,  to  inorganic  evolution  and  cos- 
mical  problems,  has  not  been  covered  in  one  book  for  general  readers. 
The  author1!  wide  experience  has  shown  the  need  of  a  popular  syn- 
thesis of  the  new  discoveries  in  science  which  separately  have  been 
making  so  profound  an  impression,  and  his  book  may  be  recommended 
to  all  whether  readers  or  students  who  have  followed  the  significant 
announcements  made  from  time  to  time  in  behalf  of  such  scientists  as 
Becquerel,  the  Cuiies,  Ramsay,  Crookes,  and  others.  Prof.  Duncan 
gives  a  general  view  of  the  newest  knowledge  of  science  and  its 
possibilities. 

With  many  illustrations.        8vo.        Cloth.        $2.00  net 

(  Others  in  preparation.  ) 


A.    S.     BARNES     &     COMPANY 
1 56  FIFTH  AVENUE,    NEW  YORK 


THE  NEW  KNOWLEDGE 


A  POPULAR  A(  (  ( HXT  OF  THE  NEW  PHYSICS  AND 

THE  NEW  CHEMISTRY  IN  THEIR  RELATION 

TO  THE  NEW  THEORY  OF  MATTER 


BY 

ROBERT  KENNEDY  DUNCAN 

ii 

PROFESSOR   OF   CHEMISTRY    IX    WASHINGTON    AND   JEFFERSON 

COLLEGE 


ILLUSTRATED 


5ITY 


NEW   YORK 

A.  S.  BARNES  &  COMPANY 
1905 


QC 
9 


Copyright  1905. 
BY  A.  S.  BARNES  &  COMPANY. 

All  Rights  Reserved. 
Published  April  1905. 


TO  THE  MEMORY  OF  MY  MOTHER 


PKEFACE. 

The  historical  method  of  treatment  is  the  death  of  clear 
exposition.  Consequently,  I  have  given  scant  considera- 
tion to  the  evolution  of  the  idea  in  time  compared  with  its 
evolution  from  the  standpoint  of  simplicity  of  apprehen- 
sion. Furthermore,  what  a  man  "  wants  to  know  "  is  less 
the  doer  of  the  work  than  the  work  done.  I  have,  there- 
fore, made  the  workers  incidental  to  their  work.  Never- 
theless, these  men  represent  the  very  elite  of  the  army  of 
science.  It  is  doubtful  whether  in  any  other  field  of  hu- 
man effort  there  are  to  be  found  so  many  men  of  tran- 
scendent genius,  magnificent  training  and  splendid  balance 
of  judgment  as  are  to  be  found  in  the  science  of  radio- 
activity. It  often  happens  in  science  that  wrhen  a  new 
Alaska  is  discovered  there  is  a  rush  of  "  tenderfeet "  to 
the  district  and  it  becomes  difficult  to  extract  from  the 
mass  of  material  presented  the  pure  metal  from  the  "  fool's 
gold."  This  was  notably  the  case  with  Rontgen's  orig- 
inal discovery,  but  it  has  been  equally  not  the  case  since 
radio-activity  became  a  distinct  science.  These  men  are 
the  pride  of  their  universities;  and  their  names  and  work 
will  long  hold  out  "  against  the  wreckful  siege  of  battering 
days."  Such  are:  J.  J.  Thomson,  Becquerel,  M.  et  Mde. 
Curie,  Rutherford,  Ramsay,  Crookes,  Lodge,  C.  T.  R. 

(vii) 


Vlll  PREFACE. 

Wilson,  H.  A.  Wilson,  Elster  and  Geitel,  Soddy,  Debierne, 
McLennan,  Allan,  and  many  others. 

Their  work  consists  of  facts  experimentally  obtained  and 
theories  based  upon  these  facts.  Their  statements  of  fact 
may,  emphatically,  be  believed,  and  I  trust  that  I  have  not 
trifled  with  them.  Their  theories  are  as  they  would  have 
them — acceptable  so  long  as  they  explain  the  phenomena 
observed.  As  these  theories  are  presented  in  this  book, 
they  cannot  be  said  to  rest  upon  any  definite  concensus  of 
scientific  opinion.  The  science  is  too  new.  Each  theory 
is,  rather,  the  work  of  some  one  man  who  is  entitled  to 
speak  as  the  authority  paramount  on  that  particular  sub- 
ject. I  have  taken  them  as  so  many  defensible  theses  and 
have  presented  them  as  clearly  and  forcibly  as  I  might. 

If  any  portion  of  this  book  seems  a  little  too  enthusiastic 
it  is  due  to  a  vast  admiration  for  the  work  of  these  mas- 
ters of  science. 

R.  K  D. 

Washington  and  Jefferson  College, 
Washington,  Pa.,  January,  1905. 


TABLE  OF  CONTENTS. 


Introduction. 

Part  1.  Current  Conceptions. 

CHAPTER        I.  THE  THREE  ENTITIES.  1 

II.  COMPOUNDS   AND    ELEMENTS:    MOLE- 
CULES AND  ATOMS.  8 

Part  2.  The  Periodic  Law. 

CHAPTER        I.  THE  MYSTERY  OF  MATTER.  15 

II.  THE  ATOMS  OF  THE  ELEMENTS.  17 

III.  THE  TABLE  OF  THE  LAW.  26 

IV.  THE  TESTING  OF  THE  LAW.  34 
V.  THE  SIGNIFICANCE  OF  THE  LAW.  39 

Part  3.  Gaseous  Ions. 

CHAPTER  I.  GASES  FROM  THE  STANDPOINT  OF 
PHYSICS  :  How  THEY  CONDUCT 
ELECTRICITY.  45 

II.  DISCOVERY  OF  IONS  :  A  NEW  KIND  OF 

PARTICLES.  48 

III.  DISCOVERY  OF  CORPUSCLES.  51 

IV.  FACTORS  OF  A  CORPUSCLE  :   AN  EX- 

PERIMENT. 54 

V.  THE  SPEED  OF  A  CORPUSCLE  AND  How 

IT  is  ESTIMATED.  59 

VI.  THE  RELATION  OF  THE  CHARGE  ON  A 
CORPUSCLE  TO  ITS  MASS:  How  IM- 
PORTANT IT  is.  61 

(ix) 


X  TABLE    OF   CONTENTS. 

CHAPTER  VII.  How  THE  ELECTRICAL  CHARGE  ON  A 
CORPUSCLE  is  ESTIMATED:  A  NEW 
USE  FOR  CLOUDS.  63 

VIII.  How  THE  MASS  OF  A  CORPUSCLE  is 
DETERMINED:  DISCOVERY  OF  THE 
ONE  THING.  65 

IX.  PROPERTIES  OF  CORPUSCLES  :  CATHODE 

RAYS.  67 

X.  POSITIVE  IONS:  THE  OTHER  KIND  OF 

PARTICLES.  76 

Part  4.  Natural  Radio-activity :  A  New  Property  of  Matter. 
CHAPTER        I.  ANTECEDENT  DISCOVERY.  81 

II.  DISCOVERY  OF  RADIO-ACTIVITY.  86 

III.  DISCOVERY    OF    RADIO-ACTIVE     ELE- 

MENTS. 90 

IV.  RADIUM.  93 
V.  BECQUEREL  RAYS  FROM  RADIUM.            96 

VI.  THE  ALPHA-,  BETA-,  AND  GAMMA- RAYS.  105 
VII.  EMANATIONS.  112 

VIII.  EMANATION    X     AND   THE  BIRTH  OF 

HELIUM.  122 

IX.  THORIUM,   URANIUM,  POLONIUM    AND 

ACTINIUM.  126 

X.  RADIO-ACTIVITY  EVERYWHERE.  133 

Part  5.  The  Resolution  of  the  Atom. 

CHAPTER        I.  MODERN    ALCHEMY:    THE    TRANSMU- 
TATION OF  MATTER.  137 
II.  ATOMIC    DISINTEGRATION:     AN    AT- 
TEMPT TO  EXPLAIN    THE   MYSTKKY 
OF  MATTER.  150 

III.  INTER-ATOMIC  ENBHGY,  172 

IV.  THE  ELECTRICAL  NATURE  OF  MATTER.  179 


TABLE   OF   CONTENTS.  XI 

Part  6.  Inorganic  Evolution. 

CHAPTER         I.  CELESTIAL  DISSOCIATION.  193 

II.  INORGANIC  EVOLUTION.  206 

III.  INORGANIC  DEVOLUTION*.  217 

Part  7.  The  New  Knowledge  and  Old  Problems. 
CHAPTER         I.  COSMIC AL  PROBLEMS.  227 

II.  THE  MECHANICAL  PRESSURE  OF  LIGHT 

AND  ITS  CONSEQUENCES.  232 

III.  THE     RECONSTRUCTION     OF    A    UNI- 

VERSE. 241 

IV.  THE    DEFINITIONS    OF    SCIENCE    RE- 

DEFINED. 246 

V.  THE  VALIDITY  OF  THE  NEW    KNOWL- 
EDGE. 252 


ILLUSTRATIONS. 


FIG.  PAGE 

1 .  RADIOMETER 4 

2.  PERIODICITY  OF  ATOMIC  VOLUMES 24 

3.  PERIODICITY  OF  MELTING-POINTS 25 

4.  FIRST  PART  OF  MENDELEEFF'S  TABLE 26 

5.  THE  LATEST  TABLE  OF  THE  PERIODIC  LAW 28 

6.  RELATIONSHIP  IN  GROUP  II 31 

7.  RELATIONSHIP  IN  GROUP  VII 32 

8.  AN    ELECTROSCOPE 47 

9.  APPARATUS  FOR  PROVING  THE  CONDUCTIVITY  OF  THE  AIR  49 

10.  SHOWING  THE  DIVISION  OF  A  FLAME  BETWEEN  OPPOSITELY 

CHARGED  PLATES 50 

11.  APPARATUS  FOR  STUDYING  IONS  FROM  A  HOT  WIRE 51 

12.  EXPERIMENT    FOR    DETERMINING    THE    VELOCITY    OF    A 

CORPUSCLE 56 

13.  SHOWING  RAYS  DEFLECTED  BY  HORSE-SHOE  MAGNET.  ...  57 

14.  SHOWING  PHENOMENA  IN  VACUUM  TUBE.  . 68 

15.  SHOWING    THAT    THE    PHOSPHORESCENCE    ARISES    FROM 

THE  CATHODE 68 

16.  PHOTOGRAPHIC    REPRESENTATION    OF    A    VACUUM   TUBE 

IN  ACTION 69 

17.  CATHODE  RAYS  OF  CORPUSCLE  BROUGHT  TO  A  Focus. ...  71 

18.  SHOWING  THAT  CORPUSCLES  WILL  MOVE  A  BODY  WHICH 

THEY  STRIKE 71 

19.  XlEWENGLOWSKl's      EXPERIMENT 83 

20.  THE  RESULT  OF  XIEWENGLOSKI'S  EXPERIMENT 84 

21.  BECQUEREL'S  FIRST  EXPERIMENT 87 

22.  URANIUM  RADIOGRAPH 88 

23.  PHOTOGRAPH  OF  A  SECTION  OF  PITCHBLENDE 91 

24.  RADIOGRAPH  OF  A  SECTION  OF  PITCHBLENDE 91 

25.  COMPARATIVE  SPECTRA  OF  RADIUM  AND  CALCIUM 93 

20.     RADIOGRAPH    SHOWING    THE    PENETRATIVE    POWER    OF 

RAYS    FROM    RADIUM 96 

27.     RADIOGRAPH  BY  THE  CURIES 97 

28   (a).     RADIUM  CHLORIDE,  PHOTOGRAPHED  BY  DAYLIGHT 98 

(xiii) 


XIV  ILLUSTRATIONS. 


FIG.  PAGE 

28  (6).     RADIUM  CHLORIDE,  PHOTOGRAPHED  BY  THE  LIGHT  OF  ITS 

PHOSPHORESCENCE 98 

29  (a).     AN  ELECTROSCOPE,  CHARGED 99 

29    (6).     THE  SAME  ELECTROSCOPE  DISCHARGED  BY  RADIUM 100 

30.  M.  BECQUEREL  AND  THE  EXPERIMENT  WITH  THE  MAGNET  101 

31.  MAGNETIC  DEVIATION  OF  THE  BECQUEREL  RAYS 102 

32.  RADIOGRAPH    SHOWING    THE    PENETRATIVE    POWER    OF 

RAYS  FROM  RADIUM 102 

33.  BECQUEREL  RAYS  CONSIST  OF  AT  LEAST  Two  KINDS.  . . .   103 

34.  ANOTHER  PROOF 103 

35.  SECTION  OF  CROOKE'S  SPINTHARISCOPE 106 

36.  PHOSPHORESCENCE  INDUCED  BY  INDUCED  RADIO-ACTIVITY  113 

37.  CURIE'S  EXPERIMENT  PROVING  THE  EXISTENCE   OF  AN 

EMANATION 114 

38   (a).     CURIE'S  ELECTROSCOPE  FOR  THE  STUDY  OF  RADIO-ACTIVITY  117 

38    (6).     DIAGRAMMATIC  REPRESENTATION  OF  FIG.  38  (a) 117 

39.  CURVES  SHOWING  THE  RATE  OF  RECOVERY  OF  THE  RADIUM 

AND  THE  DECAY  OF  THE  EMANATION 120 

40.  THE  SPECTRUM  OF  HELIUM 125 

41.  CURVES  SHOWING  THE  RATE  OF  RECOVERY  OF  THORIUM 

AND  THE  DECAY  OF  THORIUM  X 127 

42.  THE  ARRANGEMENT  OF  Two  CORPUSCLES 154 

43.  THE  ARRANGEMENT  OF  THREE  CORPUSCLES 154 

44.  THE  CONFIGURATIONS  ASSUMED  BY  FLOATING  MAGNETS.  .   156 

45.  A  CONTINUOUS  AND  A  DISCONTINUOUS  SPECTRUM 195 

46.  PARTS  OF  THE  SPECTRA  OF  BARIUM  AND  IRON 195 

47.  FLUTINGS  OF  CARBON 196 

48.  SERIES  SPECTRA  IN  THE  CLEVEITE  GASES 196 

49.  FRAUNHOFER'S  LINES. 198 

50.  IRON  SUN-SPOT  LINES  AT  KENSINGTON  CONFRONTED  WITH 

IRON  PROMINENCE-LINES  AT  PALERMO 202 

51.  DIFFERENT  RATES  OF  MOTION  REGISTERED  BY  DIFFERENT 

IRON   LINES 203 

52.  DIAGRAM  SHOWING  THE  DURATION  OF  ORGANIC  EVOLU- 

TION COMPARED  WITH  INORGANIC  EVOLUTION 215 

53.  SPECTRA  SHOWING  AN  INORGANIC  DEVOLUTION 219 

54.  THE  PROGRESS  OF  A  NEBULA  TO  A  DARK  STAR.  .  .  223 


INTRODUCTION. 


Laymen  in  science  who  wish  to  follow  the  trend  of  modern 
discovery  are  limited  for  the  most  part  to  one  of  two  things : 
Either  they  must  read  the  pseudo-science  of  the  magazines, 
which  is  arranged  chiefly  for  dramatic  effect  rather  than 
for  accurate  exposition,  or  they  must  turn  to  specialized 
and  technical  works  written  by  the  discoverers  themselves 
for  their  fellow-workers — books  in  which  technical  training 
is  taken  for  granted,  and  the  lay  reader,  however  cultured 
and  thoughtful  he  may  be,  becomes  utterly  and  hopelessly 
lost. 

The  world  is  thus  divided  between  men  who  know  and 
cannot  tell,  and  men  who  tell  and  cannot  know.  The  great 
expositors  are  dead,  Huxley  and  Tyndall  and  all  the  others; 
and  the  great  expositor  of  the  future,  the  interpreter  of 
knowledge  to  the  people,  has  still  to  be  born.  The  writer 
of  this  book,  himself,  falls  under  the  burden  of  these  difficult 
conditions.  He  dares  venture  the  undertaking  only  be- 
cause of  the  need  of  some  interpretation  of  this  new  and 
interesting  knowledge  and  because  of  his  own  sincerity. 
He  expects  nothing  from  the  reader  but  a  high  school 
education  and  a  love  of  contemporary  natural  knowledge. 
This  love  of  contemporary  natural  knowledge  is  legitimate. 
There  is  something  peculiarly  attractive  about  this  border- 
line between  science  and  ignorance.  It  is  the  fighting- 
line — and  it  is  so  pre-eminently  human  and  natural  to  love 
the  spectacle  of  a  struggle.  It  is  the  spectacle  of  a  con- 

(XV) 


XVI  INTRODUCTION. 

temporary  struggle  that  the  author  places  before  the  reader, 
the  casus  belli  being  neither  more  nor  less  than  the  nature 
of  the  chemist's  atom.  The  nature  of  the  atom  may  seem 
at  first  sight  to  be  too  abstruse  and  remote  to  enter  into  the 
sphere  of  practical  interest.  Such  a  hasty  judgment  would 
be  unwarranted.  The  atoms  of  matter  are  the  bricks  of 
the  universe,  out  of  which  you  and  we  and  the  Milky  Way 
and  the  Dog  Star  are  all  made  up.  What  affects  the  atom 
affects  us.  As  a  matter  of  fact,  there  is  nothing  esoteric 
about  it  and  little  that  is  abstract.  The  knowledge  is  ap- 
prehendable  enough  and  vastly  important.  Locked  up  in 
it  is  the  cause  of  the  heat  of  the  sun,  together  with  the  nature 
of  electricity,  .the  evolution  of  a  universe  and  the  birth  and 
decay  of  matter.  There  are  also,  possibly,  a  cure  for  tubercu- 
losis, light  without  heat,  a  demonstration  of  vast  stores  of 
energy  hitherto  unsuspected,  beside  which  the  forms  of  en- 
ergy with  which  we  are  acquainted  are  absolutely  insignifi- 
cant, and  a  whole  series  of  radiations  heretofore  unknown 
from  matter  in  the  natural  state.  Ten  years  ago  men  talked 
with  extreme  positiveness  about  this  and  that;  a  famous 
litterateur,  even,  wrote  a  comprehensive  treatise  on  "The 
Bankruptcy  of  Science"  in  which  he  proved  (sic)  that  every- 
thing essential  and  possible  of  knowing  was  known,  and  that 
all  that  remained  was  mere  detail.  It  is  proper  to  say  that 
the  answer  of  science  to  this  tremendous  indictment  was  in 
deeds,  not  words,  for  there  came  in  rapid  succession  Hertz' 
discovery  of  electro-magnetic  waves,  Moissan's  revolu- 
tionary work  with  the  electric  furnace,  Kontiren's  X-rays, 
Rayleigh's  and  Ramsay's  discovery  of  the  rare  gases  of  the 
at  mosphere,  and  Dewar's  liquefaction  of  hydrogen.  Finally, 
there  has  come,  as  most  upsetting  to  all  preconceived  ideas, 
the  famous  discovery  of  Becquerel  and  the  Curies,  which  in 
itself  and  in  its  consequences  forms  mainly  the  subject- 


INTRODUCTION,  xvii 

matter  of  this  book.  Where  before  there  was  solid,  walk- 
able  ground  to  the  older  science,  now  there  is  nothing  but 
shifting  sand.  The  last  century  began  with  the  atom,  and 
the  result  is  the  implements  of  civilization  as  we  have  them. 
This  century  begins  with  the  atom  within  the  atom,  and,  if 
one  may  judge,  the  civilization  of  the  coming  years  will  be 
rapidly  modified  and  eventually  transformed  into  phases  of 
which,  now,  we  have  but  the  barest  glimpse. 

Since  it  has  been  the  cardinal  desire  of  the  writer  to  make 
this  book  a  logical  sequence  and,  to  some  extent,  a  synthesis 
of  this  new  knowledge,  he  has  deemed  it  advisable  to  begin 
with  definitions  which  formulate  the  fundamental  concep- 
tions of  the  older  science  and  to  build  the  book  up  to  the 
definitions,  re-defined,  which  sum  up  the  advance.  Only  in 
this  way  can  the  general  reader  obtain  a  reasonably  com- 
prehensive grasp  of  the  subject-matter  and  only  in  this 
way,  also,  can  the  writer  force  upon  him  an  intellectual 
conviction  of  its  validity. 

Since  there  appears  to  be  no  text-book  which  even  at- 
tempts to  cover  this  field  of  knowledge  it  is  hoped  that 
this  simple  gathering  together  of  its  most  significant  facts 
and  theories  may  prove  useful  and  helpful  to  the  teacher 
and  the  student. 

The  progressive  teacher,  particularly  in  the  high  school 
or  smaller  college,  finds  it,  often,  exceedingly  difficult  to 
gain  access  to  the  original  sources  of  knowledge. 

The  student,  whether  he  is  now  in  school  or  college  or 
whether  he  has  passed  therefrom  into  his  life-work  of  me- 
chanical or  professional  activity,  generally  has  not  time  for 
and  does  not  desire  such  original  sources,  though  he  may 
have  an  eager  wish  to  keep  abreast  of  the  march  of  knowl- 
edge. 

Teachers  and  advanced   students  of  branches  of  knowl- 


Xviii  INTRODUCTION. 

edge  widely  divergent  from  physical  science  often  wish  to 
correlate  their  knowledge  with  its  latest  thought.  To  them 
as  well  as  to  general  readers  it  is  hoped  that  the  simple  ex- 
position and  summary  offered  in  this  book  may  prove  con- 
venient, acceptable  and  useful. 

R.  K.  D. 


PART  I. 

CURRENT  CONCEPTIONS. 


"Now,  whether  the  main  outlines  of  the  world-picture  which 
I  li'irc  just  imperfectly  presented  to  you  be  destined  to  survive, 
<>r  irhcther  in  their  turn  they  are  to  be  obliterated  by  some  new 
drawing  on  the  scientific  palimpsest,  all  will,  I  think,  admit 
that  so  bold  an  attempt  to  unify  physical  nature  excites  feelings 
of  the  most  acute  intellectual  gratification.  The  satisfaction 
rs  is  almost  aesthetic  in  its  intensity  and  quality.  We 
feel  the  same  sort  of  pleasurable  shock  as  when  from  the  crest 
of  some  melancholy  pass  we  first  see  far  below  us  the  sudden 
</lories  of  plain,  river,  and  mountain." 

"Reflections  Suggested  by  the  New  Theory  of  Matter."  Inaugural 
AiMri-ss  by  the  RIGHT  HON.  A.  J.  BALFOUR,  PRESIDENT  OF  THE  BRITISH 
ASSOCIATION.  August,  19(4. 


THE  NEW   KNOWLEDGE. 


PART  I. 
CURRENT 


CHAPTER  I. 

THE  THREE  ENTITIES. 

When  a  man  begins  to  think,  seriously,  of  the  world,  or 
worlds,  around  about  him,  he  is  at  first  dazed  by  the  seeming 
complexity  of  it  all.  Thousands  of  phenomena  confront 
him,  inextricably  tangled,  and  there  seems  to  be  no  simple 
way  of  co-ordinating  them.  That  the  universe  must  be 
harmonious,  is  a  fundamental  demand  of  our  human  nature. 
Nor  is  this  faith  misplaced.  Just  so  soon  as  we  actually 
begin  to  sort  things  out,  matters  proceed  with  gratifying 
smoothness  and  it  soon  becomes  apparent  that  one  may 
place  all  he  knows  of  this  universe  of  space  and  time  into 
just  exactly  three  compartments.  These  compartments  we* 
shall  label: 

1.  MATTER. 

2.  ETHER. 

3.  ENERGY. 

These  are  three  physical  entities,  outside  of  which,  so 


2  THE  NEW  KNOWLEDGE. 

far  as  we  understand  the  physical  universe,  there  is  noth- 
ing, and  into  which  the  universal  content  of  the  mind  of 
man,  so  far  as  it  concerns  things  outside  itself,  may  be  stowed 
away.  For  the  sake  of  our  atom,  we  must  define  these  three 
entities,  and,  until  the  progress  of  our  book  warrants  it, 
we  must  define  them  by  means  of  the  current  conceptions. 

MATTER. 

AY  hat  matter  is,  in  itself  and  by  itself,  is  quite  hopeless 
of  answer  and  concerns  only  metaphysicians.  The  "Ding 
an  sich"  is  forever  outside  the  province  of  science.  If  all 
men  stopped  to  quarrel  over  the  inner  inwardness  of  things, 
progress,  of  course,  would  cease.  Science  is  naive;  she 
takes  things  as  they  come,  and  rests  content  with  some 
such  practical  definition  as  will  serve  to  differentiate  matter 
from  all  other  forms  of  non-matter.  This  may  be  done, 
strictly  provisionally  in  this  place,  by  defining  matter  as 
that  which  occupies  space  and  possesses  weight.  Using 
these  two  properties  it  is  readily  possible  to  sift  out  matter 
from  all  the  heterogeneous  phenomena  that  present  them- 
H'lves  to  the  senses,  and  that,  in  this  place,  is  what  we  want. 
Thus,  wood,  water,  copper,  oil  and  air  are  forms  of  matter 
for  they  evidently  possess  weight  and  fill  space.  But  light, 
heat,  electricity  and  magnetism  we  cannot  consider  to  fill 
so  many  quarts  or  weigh  so  many  pounds.  They  are,  there- 
fore, forms  of  non-matter.  In  like  manner,  things  such 
as  grace,  mercy,  justice  and  truth,  while  they  are  existing 
entities  as  much  as  matter,  are  unquestionably  non-matter. 

^•-  havi  jiiently,  in  this  definition,  a  ready  touch- 

fnr  distinguishing  matter  from  non-matter. 

Now,  p>vcniin<:  matter  in  all  its  varied  forms,  there  is 
one  great  fundamental  law  which  up  to  this  time  has  been 
ironclad  in  i1  irr 


THE   THREE    ENTITIES.  6 

This  law,  known  as  the  law  of  the  conservation  of  mass, 
states  that  no  particle  of  matter,  however  small,  may  be 
created  or  destroyed.  All  the  king's  horses  and  all  the 
king's  men  cannot  destroy  a  pin's  head.  We  may  smash 
that  pin's  head,  dissolve  it  in  acid,  burn  it  in  the  electric 
furnace,  employ,  in  a  word,  every  annihilating  agency,  and 
yet  that  pin's  head  persists  in  being.  Again,  it  is  as  un- 
creatable  as  it  is  indestructible.  In  other  words,  we  cannot 
create  something  out  of  nothing.  The  material  must  be 
furnished  for  every  existent  article.  The  sum  of  matter 
in  the  universe  is  x  pounds, — and,  while  it  may  be  carried 
through  a  myriad  forms,  when  all  is  said  and  done,  it  is 
just — x  pounds. 

In  the  foregoing  statements  we  have  used  the  conceptions 
of  the  older  science,  and,  indeed,  the  current  conceptions; 
but  to  say  that  throughout  all  time  we  never  should  be 
able  to  destroy  or  create  matter,  or  to  say,  indeed,  that 
matter  is  not,  to  some  extent,  being  created  and  destroyed 
to-day,  would  be  to  run  the  risk  of  profound  error.  All  we 
can  say,  to-day,  is  that  we  cannot  do  it.  If  creation  or 
annihilation  is  actually  going  on,  we  are  mere  spectators  and 
stand  in  no  causal  relation.  That  this  well  may  be,  and 
probably  is,  it  must  be  the  duty  of  our  book  to  disclose  in 
certain  succeeding  pages. 

ETHER. 

Any  discussion  of  ether  leads  out  upon  the  highroad  to 
incredulity.  A  thing  must  be  defined  by  its  properties 
and  the  properties  of  the  ether  are  for  the  most  part  nega- 
tive; so  negative,  indeed,  are  they,  that  when  one  says 
boldly  that  we  cannot  see  ether,  hear  it,  taste  it,  smell  it,  ex- 
haust it,  weigh  it,  or  measure  it,  one  feels  timid  that  sane- 
minded  people  will  meet  these  negative  qualities  of  our 


THE    NEW    KNOWLEDGE. 


other  by  a  decided  negation  of  belief  in  its  existence.  But 
the  fact  of  the  matter  is  that  if  this  thing  "ether"  is  not 
visible  to  the  eye  of  sense  it  is  visible  to  the  eye  of  the  mind, 
which  is  much  less  liable  to  err.  To  demonstrate  this, 
place  a  little  instrument  known  as  the  radiometer  up  in  the 
sunlight.  This  instrument  consists  of  a 
glass  bulb  containing  a  partial  vacuum  in 
which  hangs  poised  a  tiny  mill  wheel  of 
aluminum.  On  the  impact  of  the  sunlight 
the  wheel  at  once  begins  to  revolve,  and 
soon  attains  a  velocity  so  great  that  the 
eye  is  unable  to  distinguish  the  separate 
vanes.  Now  the  eye  of  the  mind  is  applied : 
Something,  therefore,  flies  93,000,000  of 
miles  from  the  sun  and  causes  that  wheel 
to  revolve,  and  that  something  must  be 
the  radiations  of  light  and  heat.  With  re- 
gard to  the  nature  of  these  radiations  we 
are  positively  shut  up  to  one  of  two  ex- 
planations. 

The  light  and  heat  proceeding  from  the  sun  consist 
either  of  particles  or  of  waves.  There  is  no  other  explana- 
tion conceivable. 

The  first  assumption,  that  they  consist  of  particles,  is 
known  as  the  "corpuscular  theory,"  and  was  killed  out- 
right and  buried  years  ago  after  a  battle  royal.     The  second 
assumption,  that  of  waves,  known  as  the  undulatory  theory, 
with  universal  acceptance.     It  is  the  only  complete 
explanation  of  all  the  known  facts.     The  radiations  from 
the  sun,  therefore,  that   moved  our  mill  wheel  consist  of 
waves;  and  now  comes  the  inevitable  back-thrust  of  the 
mind,  waves  of  what? 
Once  convinced  that  light   consists  of  waves,  the  mind 


THE    THREE    ENTITIES.  5 

insists  that  those  waves  shall  inhere  in  something.  The 
ocean  waves  are  made  of  water, — sound  waves  of  air,— 
light  waves  of,  we  must  say, — something.  This  something 
cannot  be  air  or  water  or  any  form  of  matter  as  we  know  it, 
for  throughout  that  great  reach  of  93,000,000  of  miles  be- 
tween the  sun  and  us  there  exists  but  empty  space.  Filled 
this  empty  space  is,  however,  and  to  the  brim.  There  is  no 
such  thing  as  emptiness.  From  corner  to  corner  of  the 
universe,  wherever  a  star  shines  or  light  darts,  there  broods 
this  vast  circumambient  medium — the  ether.  Not  only 
through  interstellar  spaces,  but  through  the  world  also,  in 
all  its  manifold  complexity,  through  our  own  bodies;  all  lie 
not  only  encompassed  by  it  but  soaking  in  it  as  a  sponge 
lies  soaked  in  water.  How  much  we  ourselves  are  matter 
and  how  much  ether  is,  in  these  days,  a  very  moot  question. 

ENERGY. 

Just  as  there  is  no  such  thing  as  emptiness,  so  there  is 
no  such  thing  as  rest.  It  is  doubtful  that  there  is  such  a 
thing  as  rest  even  in  a  relative  sense.  The  very  particles 
that  constitute  the  materials  of  our  so-solid-seeming  earth, 
that  seem  so  fixed  and  at  rest  relatively  to  one  another  are 
in  a  state  of  perpetual  unremitting  quiver — what  we  call 
temperature — and  that  quivering,  had  we  eyes  but  big 
enough  to  see  it,  is  very  far,  indeed,  removed  from  rest. 
Now,  this  motion  is  continually  changing,  from  one  velocity 
to  another,  and  the  same  kind  of  reasoning  that  led  us  to 
believe  in  the  ether  leads  us  to  believe  that  a  body  can  go 
faster  or  slower  only  because  of  some  cause.  This  cause, 
or  this  power  to  change  the  state  of  motion  of  a  body,  is 
energy. 

Just  as  matter  may  exist  in  so  many  different  forms,  so 
may  energy,  a  list  of  the  forms  of  which  we  append: 


6  THE   NEW   KNOWLEDGE. 

1.  KINETIC   ENERGY.  6.    CHEMICAL    ENERGY. 

2.  GRAVITATION    ENERGY.  7.    ELECTRICAL   ENERGY. 

3.  HEAT.  8.    MAGNETIC    ENERGY. 

4.  ENERGY   OF   ELASTICITY.  9.    RADIANT   ENERGY. 

5.  COHESION    ENERGY. 

This  list  comprises  "forms"  of  energy  and  not  " differ- 
ent energies,"  for  the  reason  that  they  are  one  and  all  inter- 
convertible. Energy  is  protean  in  its  nature  for  it  may  be 
converted,  directly  or  indirectly,  into  any  other  form.  They 
are,  therefore,  different  phases  of  one  thing,  not  different 
things.  For  example,  the  energy  of  the  burning  coal  is 
converted  consecutively  into  heat,  into  mechanical  energy, 
into  electrical  energy,  and,  finally,  in  some  far  away  street, 
into  the  radiant  energy  of  the  arc  lamp.  It  is  possible, 
even,  that  these  very  " forms"  may  not  be  distinct  from 
one  another,  actually,  but  are  simply  so  many  different 
varieties  of  motion. 

However  that  may  be,  energy  is  not  only  transformable 
but  transferable.  In  a  word,  we  may  transfer  energy  from 
one  body  to  another  indefinitely.  We  may  load  the  energy 
from  a  waterfall  into  a  dynamo  and  from  the  dynamo  into  a 
sowing  mad  line.  Matter  is  but  a  stepping-stone  to  energy, 
here  and  away,  through  one  form  to  another  and  from  one 
body  to  another,  infinitely  restless,  constant  only  to  one 
tiling,— its  total  <|uantity.  However  much  energy  may  be 
lormod  or  transferred,  when  any  quantity  of  one  form 
di-appoars.  a  precisely  equal  quantity  simultaneously  ap- 
pears in  some  other  form  or  forms.  Just  as  with  matter, 
you  cannot  create  or  destroy  any  quantity  of  energy  liow- 
!l,  and  since  energy  is  the  great  worker  of  the 
nnivcrH-  you  cannot  get  something  for  nothing.  No  ma- 
rhino  can  make  energy,  and  it  is  curious  that  this  fact  is 


THE   THREE    ENTITIES.  7 

so  little  understood  of  men,  that,  according  to  rumour,  the 
Patent  Office  finds  it  necessary  to  employ  a  special  clerk 
to  deal  with  persons  who  believe  in  perpetual  motion.  It 
will  readily  be  seen,  then,  that  since  energy  may  be  trans- 
formed from  one  form  into  another,  since  it  may  equally 
well  be  transferred  from  one  body  to  another,  and  since, 
moreover,  it  cannot  be  created  or  destroyed,  we  have  pre- 
cisely the  same  grounds  for  believing  in  its  existence  as  an 
actual  entity  as  we  had  for  believing  in  the  existence  of 
matter.  It  is  proper  for  us  to  hold  as  reasonable  the  view 
that  energy  is  an  existing  "  thing."  Concerning  the  dictum 
of  current  science,  that  it  is  impossible  to  create  or  destroy 
it,  we  ought  to  make  the  same  provision  as  we  did  with 
matter,  that  while  it  may  not  be  forever  and  forever  in- 
destructible and  uncreatable,  and  while  it  may  be  even  now 
suffering  annihilation,  we  have  no  control  over  it.  The 
doctrine  of  the  conservation  of  energy  is  receiving  some 
hard  knocks  nowadays,  and  whether  or  not  it  is  weaken- 
ing will  be  for  the  future  to  determine. 

We  have,  thus,  reduced  the  universe  to  three  terms: 
matter — ether — energy,  and  we  ought  now  to  consider 
whether  this  triune  conception  may  not  be  capable  of  a 
deeper  synthesis.  We  have  all,  I  imagine,  a  deep-seated 
conviction  of  the  essential  " oneness"  of  the  universe,  and 
to  justify  it,  we  must  assume,  either  that  these  three  things 
are  after  all  but  " forms"  or  phases  of  an  underlying  and 
unknowable  reality,  or  that,  separate  and  distinct  as  they 
appear,  they  are  themselves  One,  in  some  mysterious  way 
altogether  beyond  the  power  of  human  reason  to  grasp. 


CHAPTER  II. 
COMPOUNDS  AND  ELEMENTS:  MOLECULES  AND  ATOMS. 

The  number  of  the  forms  of  matter,  that  is,  of  the  different 
weighable,  space-filling  things,  in  our  world  reaches  an  as- 
tonishing total. 

Two  hundred  and  fifty  thousand  would,  probably,  be  a 
modest  estimate  of  the  number  of  things  having  properties 
that  sharply  demarcate  them  from  every  other  individual 
thing.  It  is  a  simple  fact  that  if  one  were  to  attempt  to 
read  all  the  accounts  of  the  different  forms  of  matter  daily 
discovered,  as  they  appear  in  the  journals  of  science,  one 
would  certainly  hopelessly  fail,  reading  twenty-four  hours 
in  the  day.  These  substances  are  known  as  the  "  com- 
pounds" of  matter. 

Compounds,  however,  while  they  are  individual  in  their 
properties  are  not  simple  in  their  composition.  Common 
salt  may  be  broken  down  into  a  metal  that  floats  on  water, 
called  sodium  and  a  greenish-yellow  gas  called  chlorine; 
prussic  acid  may  be  decomposed  into  two  gases  called  hy- 
drogen and  nitrogen  and  into  a  solid  called  carbon.  In  fact, 
every  one  of  this  vast  number  of  heterogeneous  substances 
may  be  broken  down  successively  into  simpler  bodies  that 
weigh  less  than  the  substances  from  which  they  are  ab- 
Btracted;  and  these  simpler  bodies,  some  seventy  in  all, 
constitute  the  chemist's  so-called  "elements"  of  matter. 
These  elements,  in  their  properties,  have  no  relation  to  the 
substance  which,  when  united  together  in  various  ways, 
they  comprise.  Snmo  of  them,  such  as  iron,  sulphur  or 
phosphorus,  may  exist  free  or  combined,  as  the  case  may 
(8) 


COMPOUNDS  AND   ELEMENTS.  9 

be,  others,  such  as  calcium,  ca?sium  or  fluorine,  are  always 
combined  and  you  never  see  them  as  such.  They  may  be 
common  as  dirt  or  a  thousand  times  rarer  than  gold.  The 
important  point  is  that,  united  together  by  a  force  called 
chemical  affinity,  in  various  ways  and  in  different  quan- 
tities, these  same  seventy  things  constitute  all  that  is. 
But  these  things  are  found  all  over.  If  the  world  is  made 
of  "mud,"  so  are  the  sun  and  stars.  They  consist  of  the 
same  thing.  Iron  and  hydrogen  are  found  in  the  sun, 
together  with  many  an  other  element;  calcium  and  man- 
ganese in  the  great  star  Sirius;  carbon,  the  so-called  "  ele- 
ment of  life"  in  all  the  stars  alike.  The  chemistry  of  all 
parts  of  space  is  the  same. 

A  Compound  is  thus  a  substance  that  may  be  decomposed 
or  separated  into  other  substances. 

An  Element  is  a  substance  that  has,  so  far,  resisted  all 
attempts  to  decompose  it. 

MOLECULES   AND    ATOMS. 

A  substance  is  either  infinitely  divisible,  or  it  is  not. 
There  is  no  mediate  possibility.  According  to  the  old 
scholastic  conception,  you  could,  at  first  practically,  and 
then  mentally,  go  on  dividing  any  specific  object  into  parts 
smaller  and  smaller  forever  and  forever  and  forever.  In 
other  words,  you  could  never  have  a  thing  so  small  but  that 
it  had  two  halves.  Now  we  need  trouble  ourselves  with 
this  conception  no  further  than  to  say  that  it  is  absolutely 
incapable  of  explaining  the  observed  phenomena  of  the 
world.  The  fruitful  conception,  the  one  that  not  only  ex- 
plains the  phenomena  of  matter  to  an  astonishing  degree, 
but  even  permits  the  successful  prediction  of  many  forms 
of  matter  hitherto  unknown,  assumes  that  these  forms  of 
matter  as  we  know  them  are  not  by  any  means  infinitely 


10  THE   NEW  KNOWLEDGE. 

divisible,  but  that  they  consist  of  ultimate  particles — that 
matter  is  no  jelly  but  that  it  is  made  up  of  grains. 

We  believe  that,  taking  for  example  a  piece  of  common 
salt,  if  we  proceeded  to  break  it  up  finer  and  finer,  we 
should  eventually,  away  down  in  the  scale  of  fineness, 
arrive  at  a  piece  so  small,  that  if  it  were  broken  in  two 
we  should  have  no  longer  two  pieces  of  salt  resulting,  but, 
instead,  two  particles  widely  different  in  their  properties, 
namely,  a  piece  of  the  metal  sodium  and  a  piece  of  the  gas 
chlorine.  This  piece  of  salt,  so  small  that  if  we  broke  it 
the  pieces  would  no  longer  have  the  properties  of  salt,  is 
called  a  molecule  of  salt.  A  pound  of  salt  is  simply  x 
molecules  of  salt.  We  believe  that  they  move  about  each 
other,  under  the  influence  of  heat,  as  separate  bodies  and 
that  they  are  the  limit  beyond  which  it  is  impossible  to 
subdivide  matter  without  destroying  its  identity. 

ATOMS. 

We  have  said  that  when  a  molecule  of  common  salt  is 
broken  down,  there  results  a  particle  of  sodium  and  a 
particle  of  chlorine.  These  particles,  the  constituents  of 
molecules,  are  the  atoms  of  matter.  Instead,  therefore, 
of  defining  a  compound  as  a  substance  composed  of  ele- 
ments, we  may  say  that  a  compound  is  a  substance  the 
>des  of  which  are  made  up  of  the  atoms  of  the  elements. 
There  are,  of  course,  as  many  different  atoms  as  there  are 
elements.  AYlien  atoms  of  like  kind  unite  together  we 
the  elements  of  matter,  when  of  unlike  kind  the  com- 
pounds of  matter.  Now,  since  there  are  some  seventy 
dements,  there  are  some  seventy  kinds  of  atoms,  and  when 
\ve  think  of  the  varied  number  of  combinations  and  per- 
mutations >o  in  speak,  that  may 'be  brought  about  by 
tyini:  together  different  numbers  and  different  kinds  of, 


COMPOUNDS    AND    ELEMENTS.  11 

say,  seventy  odd  marbles,  it  is  no  matter  for  wonder  that 
there  are  some  two  hundred  and  fifty  thousand  different 
molecules.  A  substance  is  x  molecules,  and  a  molecule  is 
a  little  building  of  which  the  atoms  are  the  bricks.  We 
may  now  re-define  our  definitions. 

A  Molecule  is  the  smallest  particle  of  a  substance  that 
can  exist  in  a  free  state,  and  which  has  the  same  composi- 
tion as  any  larger  mass  of  the  substance. 

An  Atom  is  the  smallest  particle  of  an  element  that  exists 
in  any  molecule. 

A  Compound  is  a  substance  whose  molecule  contains  two 
or  more  kinds  of  atoms. 

An  Element  is  a  substance  whose  molecule  contains  only 
one  kind  of  atom. 


PART  II. 


THE  PEKIODIC  LAW. 


PART  II. 
THE  PERIODIC  LAW. 


CHAPTER  I. 
THE  MYSTERY  OF  MATTER. 

We  believe — we  must  believe,  in  this  day — that  everything 
in  God's  universe  of  world  and  stars  is  made  of  atoms,  in 
quantities  x,  y  or  z  respectively.  Men  and  women,  mice 
and  elephants,  the  red  belts  of  Jupiter  and  the  rings  of  Sat- 
urn AE£  one  and  all  are  but  ever  shifting,  ever  varying, 
swarms  of  atoms.  Every  mechanical  work  of  earth,  air, 
fire  and  water,  every  criminal  act,  every  human  deed  of 
love  or  valor:  what  is  it  all,  pray,  but  the  relation  of  one 
swarm  of  atoms  to  another  ? 

Here,  for  example,  is  a  swarm  of  atoms,  vibrating,  scin- 
tillant,  martial, — they  call  it  a  soldier, — and,  anon,  some 
thousands  of  miles  away  upon  the  South  African  veldt,  that 
swarm  dissolves, — dissolves,  forsooth,  because  of  another 
little  swarm, — they  call  it  lead. 

What  a  phantasmagoric  dance  it  is,  this  dance  of  atoms ! 
And  what  a  task  for  the  Master  of  the  Ceremonies.  For 
mark  you  the  mutabilities  of  things.  These  same  atoms, 
maybe,  or  others  like  them,  come  together  again,  vibrating, 
clustering,  interlocking,  combining,  and  there  results  a 
woman,  a  flower,  a  blackbird  or  a  locust,  as  the  case  may 
be.  But  to-morrow  again  the  dance  is  ended  and  the 

(15) 


16  THE    NEW  KNOWLEDGE. 

atoms  are  far  away;  some  of  them  are  in  the  fever  germs 
that  broke  up  the  dance,  others  are  "  the  green  hair  of 
the  grave/7  and  others  are  blown  about  the  antipodes 
on  the  winds  of  ocean.  The  mutabilities  of  things,  and 
likewise  the  tears  of  things:  for  one  thing  after  another, 

"Like  snow  upon  the  Desert's  dusty  Face 
Lighting  a  little  hour  or  two — is  gone/; 

and  the  eternal,  ever-changing  dance  goes  on. 

Now,  whether  we  call  the  atoms  God's  little  servants  or 
the  Devil's  agents,  one  thing  is  sure — that  every  action 
of  every  thing,  living  or  dead,  within  this  bourne  of  time 
and  space,  is  the  action  of  one  swarm  of  atoms  on  another, 
for  without  them  there  is  but  empty  void. 

Consequently,  whether  we  consider  the  atoms  as  the 
starting-place  in  our  search  "for  the  One  Thing,  or  whether 
we  think  of  them  only  as  the  foundation  of  all  physical 
action  and  being,  they  are  the  most  important  things  in 
the  world  to  us,  for  they  are  us,  physically  at  least,  and 
any  knowledge  concerning  them  or  any  relation  between 
them  has,  therefore,  to  us  poor  people  they  condition,  an 
interest  that  is  tragic. 


CHAPTER  II. 


THE  ATOMS  OF  THE  ELEMENTS. 


The  names  of  the  atoms  are  these: 


International 

Atomic  Weights  (1904). 

O=l  6. 

O=16. 

Aluminium 

..     Al 

27 

.1 

Iron          

Fe 

55 

.9 

Antimony 

..     Sb 

120 

.2 

Krypton  

Kr 

81 

.8 

A  rgon 

..     A 

39 

.9 

Lanthanum 

La 

138 

.9 

ARSENIC       .  . 

..     As 

75 

.0 

Lead         

Pb 

206 

9 

Barium 

..     Ba 

137 

.4 

LITHIUM      .  . 

Li 

7 

.03 

Bismuth 

..     Bi 

208 

.5 

Magnesium 

Mg 

24 

.36 

Boron 

..     B 

11 

MANGANESE       .  . 

Mn 

55 

.0 

BROMINE     .  . 

..      Br 

79 

.96 

MERCURY    ..      .. 

Hg 

200 

.0 

Cadmium 

..     Cd 

112 

.4 

MOLYBDENUM  .  . 

Mo 

96 

.0 

Ccesium 

..     Cs 

132 

.9 

Xeodymium    .  . 

Nd 

143 

.6 

Calcium 

..     Ca 

40 

.1 

Xeon        

Ne 

20 

CARBON 

..     C 

12 

.00 

Nickel      

Ni 

58 

.7 

Cerium 

..     Ce 

140 

.25 

NITROGEN  .  . 

N 

14 

.04 

Chlorine 

..     Ci 

35 

.45 

Osmium  

Os 

191 

Chromium 

.  :     Cr 

52 

.1 

OXYGEN       .  . 

O 

16 

.00 

COBALT 

..     Co 

59 

.0 

Palladium 

Pd 

106 

.5 

Columbium 

..     Cb 

94 

PHOSPHORUS     .  . 

P 

31 

.0 

Copper 

..     Cu 

63 

.6 

Platinum 

Pt 

194.8 

Erbium 

..     Er 

166 

Potassium 

K 

39 

.15 

Fluorine 

..     F 

19 

Praseodymium 

Pr 

140 

.5 

Gadolinium 

..     Gd 

156 

Radium    

Rd 

225 

Gallium 

..     Ga 

70 

RHODIUM     ..      .. 

Rh 

103 

.0 

Germanium     .  . 

..     Ge 

72 

.5 

Rubidium 

Rb 

85 

.4 

Glucinum 

..     Gl 

9 

.1 

Ruthenium 

Ru 

101 

.7 

Gold         .  . 

..     Au 

197 

.2 

Samarium 

Sm 

150 

Helium 

..     He 

4 

Scandium 

Sc 

44 

.1 

HYDROGEN 

..     H 

1 

.008 

Selenium  

Se 

79 

.2 

Indium 

..     In 

114 

Silicon      

Si 

28 

.4 

Iodine 

..     I 

126 

.85 

SILVER  

Ag 

107 

.93 

IRIDIUM       .  . 

..     Ir 

193 

.0 

SODIUM         .  .      .  . 

Na 

23 

.05 

2 

(17] 

1 

THE   NEW  KNOWLEDGE. 


Strontium 

su.i'iiru    . 

Tantalum 
Tellurium 

/7"?,*>*-f»Vi  i  «M 

.      ..     Sr 
.      ..     S 
.      ..     Ta 
.      ..     Te 
Tb 

O=16. 
87.6 
32.06 
183 
127.6 
160 

Titanium 
TUNGSTEN  .. 

Uranium 
Vanadium 
Xenon      .  . 

..     Ti 
..     W 
..     U 
..     V 
Xe 

O=16. 
48.1 
184.0 
238.5 
51.2 
128 

J  CTDlunl    .  * 

Thallium..      . 
Thorium  .  . 
Thulium  .  . 
TIN 

.      ..     Tl 
.      ..     Th 
.      .  .     Tin 
Bo 

204.1 
232.5 
171 
119.0 

YTTERBIT.M 
YTTRIUM     .  . 

Zinc          .  . 
Zirconium        .  . 

.  .     VI) 
..     Yt 
..      7,n 
Zf 

173.0 
89.0 
65.4 

90.6 

These  are  the  bricks  of  the  universe,  out  of  the  permuta- 
tfons  and  combinations  of  which  all  that  exists  is.  Among 
them  you  will  find  many  long-known  friends,  such  as  cop- 
per, iron,  sulphur,  silver,  and,  let  us  hope,  gold.  But 
though  many  of  them  bulk  large  in  the  world's  mass,  others 
lie  furtively  in  the  hidden  places  of  the  earth,  and  are  ob- 
tained and  isolated  only  with  infinite  trouble  and  cost. 
Thus,  indium  is  four  times,  thorium  nine  times,  caesium 
fifteen  limes,  and  very  impure  radium  thousands  of  times 
rarer  than  gold;  others  are  so  rare  that  they  cannot  be 
bought  at  all,  and  only  by  one's  own  painstaking  labor 
can  they  be  brought  to  the  light  of  day;  such  are  kryp- 
ton, praesodymium,  samarium.  Still  others  are  both  com- 
mon and  rare.  For  example,  the  silver-colored  calcium  is 
In*  rally  common  as  dirt;  it  lies  on  every  street.  Seventy- 
one  per  cent  of  every  barrel  of  lime  is  calcium,  and  yet 
calcium  is  worth  fourteen  dollars  a  thimble-full.  The  high 
cost  of  the  element  is  due  to  the  difficulty  of  extraction. 

Now,  what  are  these  sphinxes?  Are  these  atoms  sim- 
ple, independently  created,  undecomposable  little  exist- 
ences; or  will  they  tell  a  story  of  evolution  from  simpler 
existences  in  common  with  the  rest  of  creation?  What- 
story  there  is,  they  alone  can  tell  it. 

Our  present  question  is:  Are  they  related  to  one  an- 


THE  ATOMS  OF  THE  ELEMENTS.  19 

other  ?  Now,  if  there  be  any  relation  among  these  atoms, 
it  should  show  in  their  weights.  The  first  thing,  there- 
fore, we  shall  notice  is  the  number  attached  to  each  in  the 
table  above.  This  number  stands  for  the  atomic  weight ; 
in  other  words,  for  the  number  of  times  heavier  that 
particular  atom  is  than  the  hydrogen  atom  which  is  the 
lightest  and  the  unit.  These  numbers  afford  an  example 
of  the  highest  accuracy  of  hand  and  brain  that  science 
has  to  show.  It  is  true  that  if  you  look  at  the  number 
attached  to  hydrogen  you  will  find  it  placed  at  1.008  in- 
stead of  1,  as  you  would  suppose,  but  that  is  for  a  certain 
reason  that  will  soon  be  made  clear. 


PROUT'S  HYPOTHESIS. 


In  the  early  days  when  men  first  began  to  determine  the 
relative  weights  of  the  atoms,  it  was  noticed  that  the  atomic 
weights  of  quite  a  number  of  the  elements,  taking  hydrogen 
as  unity,  were  either  whole  numbers  or  very  nearly  whole 
numbers,  and  in  1815  Prout  suggested  that  this  numerical 
regularity  could  be  explained  on  the  assumption  that  the 
atoms  of  the  different  elements  were  simply  condensations 
of  the  hydrogen  atom;  for  obviously  if,  for  example,  the 
weight  of  the  oxygen  atom  were  16  and  that  of  the  carbon 
atom  wrere  exactly  12  times  as  heavy  as  the  hydrogen  atom, 
then  these  little  bodies  could  be  explained  by  assuming  that 
they  were  built  up  of  16  and  12  hydrogen  atoms  respec- 
tively,— and  there  would  be  an  end  of  the  mystery.  This 
idea  was  at  first  very  kindly  received,  but  as  men  became 
more  and  more  accurate  in  their  work,  it  was  soon  discov- 
ered that  Prout's  method  of  calmly  dropping  the  decimals 
after  the  whole  numbers  as  due  to  experimental  errors  would 
not  do,  nor  would  anything  like  it  do. 

It  became    evident    that   though  many  of    the  atomic 


20  THE    NEW    KNOWLEDGE. 

weights  were  curiously  approximate  to  whole  numbers,  they 
were  with  positive  certainty  not  whole  numbers.  The 
atomic  weight  of  oxygen,  for  example,  is  certainly  not  16, 
but  seems  to  be  established  as  15.879. 

The  decided  approximation,  however,  referred  to  above, 
was  certainly  curious,  and  it  soon  became  most  conspic- 
uously so;  for  it  turned  out  that  by  taking  the  atomic 
weight  of  oxygen  as  16  and  calculating  the  weights  of  the 
other  atoms  to  that  basis,  a  most  remarkably  large  number 
of  them  became  actually  whole  numbers,  and  another  large 
number  very  approximately  whole  numbers.  The  table  of 
the  atoms  arranged  above  is  arranged  on  the  basis  of 
oxygen =16,  which  for  certain  practical  considerations  is 
the  favorite  arrangement  among  chemists;  and  this  ex- 
plains why  the  atomic  weight  of  hydrogen  =1.008  instead 
of  1,  as  we  should  expect. 

If  you  care  to  look  at  this  table,  you  will  find  that  no 
less  than  21  (marked  in  capital  letters)  out  of  the  number 
arc  whole  numbers  to  the  second  decimal  place;  that  17  (in 
italics)  are  remarkably  approximately  so;  and  that  the  re- 
mainder drift  along  anywhere.  Now,  that  21  out  of  the  78 
arc  actually  whole  numbers,  cannot  be  accounted  for  as 
chance  on  the  basis  of  the  law  of  probability,  nor  can  the 
wonderful  approximation  of  the  other  28. 

Whatever  the  explanation  of  this  curious  approximation 
to  symmetry,  there  is  reason  enough  at  any  rate  to  suspect 
strongly  that  there  is  some  hidden  relation  here.  There  is 
enough  to  whet  our  curiosity  and  to  lead  us  on. 

TRIADS  OF  DOBEUI;IM:K. 

Another  curious  and  interesting  discovery  soon  came  to 
light.  It  became  apparent  that  out  of  the  list  of  elements 
little  groups  could  he  chosen  here  and  therewith  strongly 


THE  ATOMS  OF  THE  ELEMENTS.  21 

correlated  properties.  It  was  just  as  though,  in  a  com- 
pany of  soldiers  raised  in  the  same  village,  little  groups  of 
brothers  could  be  picked  out,  one  here  and  one  there,  owning 
to  a  strong  family  likeness.  These  little  groups  of  corre- 
lated atoms  are  known  as  the  Triads  of  Dobereiner.  Three 
such  groups  are  given  below: 

ATOMIC    WEIGHT. 

Calcium,  40'1  Chlorine,  35'4  Sulphur,  321 

Strontium,  877  Bromine,  80'0  Selenium,  79*2 
Barium,  134*4  Iodine,  126'8  Tellurium,  127'5 

The  elements  calcium,  strontium  and  barium  show  chemi- 
cal similarities  to  a  remarkable  degree.  They  look  much 
alike,  act  much  alike,  and  in  their  very  variations  vary  by 
steps.  The  same  may  be  said  of  chlorine,  bromine  and 
iodine,  or  of  sulphur,  selenium  and  tellurium. 

Now  the  curious  discovery  alluded  to  above  lies  in  the 
fact  that  if  you  take  the  mean  of  the  atomic  weights  of  the 
first  and  third  elements  in  any  of  these  groups,  you  will 
obtain,  approximately,  but  not  exactly,  the  atomic  \veight 
of  the  middle  one.  Thus: 


Atomic    weight. 
Calcium,  40.1 

Barium,  137.4 


Mean 


2)  177.5 


Chlorine,  35.4 

Iodine,  126.8 

2)16272 


Mean         81.1 


Atomic  weight 
of  Strontium,    87.7 


Atomic  weight 
of  Bromine,  80.0 


Sulphur,  32.1 

Tellurium,         127.5 


Mean     ~'S«    Atomic  weight  of  Selenium,  79.2 


22  THE    NEW   KNOWLEDGE. 

You  will  notice  that  the  mean  of  the  first  and  third  atomic 
weights  is  not  exactly  the  atomic  weight  of  the  middle  one, 
but  the  approximation  is  so  close  as  to  excite  remark  and 
to  inspire  the  conviction  that  there  is  some  hidden  reason 
for  it.  At  any  rate  our  suspicion  that  the  atoms  are  in 
some. way  or  other  related  to  one  another  is  confirmed,  and 
it  will  therefore  surprise  us  less  to  find  ourselves  confronted 
by  a  new  discovery  in 

THE   PERIODIC    LAW. 

The  Periodic  System  of  the  Elements,  as  we  now  have 
it.  was  discovered  independently  and  almost  simultaneously 
by  the  Russian,  Mendeleeff,  and  the  German,  Lothar  Meyer; 
though  the  germ  of  the  discovery  undoubtedly  lay  in  the 
Octaves  of  Newlands. 

In  1863  Mr.  John  Newlands  pointed  out  in  a  brief  letter 
to  the  Chemical  News  that  if  the  elements  be  arranged  in 
the  order  of  their  atomic  weights,  beginning  with  hydro- 
gon=l,  and  ending  with  uranium=240,  in  a  tabular  form, 
naturally  fall  into  such  groups  that  elements  similar 
to  one  another  in  chemical  behaviour  occur  in  the  same 
columns;  and  that,  moreover,  the  number  of  elements  be- 
tween any  one  and  the  next  similar  one  is  seven.  In  other 
Is,  members  of  the  same  groups  stand  to  one  another 
in  the  same  relation  as  the  extremities  of  cne  or  more  oc- 
in  music  !  This  leads  us  to  think  that  not  only  may 
then-  he  a  relation  between  these  little  fundamentals  of  the 
universe  but  a  veritable  harmony. 

Mriefly  and  technically,  the  law  states  that  "the  prop- 
of  an  element  are  a  periodic  function  of  its  atomic 

This  is  a  very  concise  statement  indeed  of  an  extraordi- 
nary fact.  The  statement  means  no  more  nor  less  than  this: 


THE  ATOMS  OF  THE  ELEMENTS.  23 

That  if  you  know  the  weight  of  the  atom  of  the  element 
you  may  know,  if  you  like,  its  properties,  for  they  are 
fixed. 

Just  as  the  pendulum  returns  again  in  its  swing,  just  as 
the  moon  returns  in  its  orbit,  just  as  the  advancing  year  ever 
brings  the  rose  of  spring,  so  do  the  properties  of  the  ele- 
ments periodically  recur  as  the  weights  of  the  atoms  rise. 
To  demonstrate  this  fact,  take  some  one  specific  property, 
for  example,  the  atomic  volume,  which  is  the  atomic  weight 
divided  by  the  specific  gravity  of  the  solid  element,  and 
arrange  a  table  on  a  piece  of  engineering  paper  in  which 
the  atomic  weights  read  from  left  to  right  (the  abscissas), 
while  the  atomic  volumes  read  from  bottom  to  top  (the 
ordinates).  Now  construct  a  curve  by  pricking  out  the  posi- 
tion of  the  different  elements  in  accordance  with  both  their 
atomic  volumes  and  atomic  weights,  and  you  will  find  your- 
self in  possession  of  a  table  such  as  Fig.  2.  We  see  at  once 
from  this  curve  that  the  atomic  volume  is  a  periodic  func- 
tion of  the  atomic  weight.  As  the  atomic  weight  increases, 
the  atomic  volume  alternately  increases  and  decreases.  The 
periodicity  proclaims  itself  in  the  regularly  recurring  hills 
and  valleys  which  constitute  the  curve.  Elements  which 
occupy  similar  positions  on  the  five  hills  and  valleys  have 
markedly  similar  properties.  Thus,  you  will  notice  at  the 
summit  of  each  of  the  five  hills,  the  symbols  of  the  ele- 
ments lithium,  sodium,  potassium,  rubidium  and  caesium, 
all  of  these  elements  possessing  amazingly  similar  properties. 
Or,  again,  find  the  little  dot  marked  S  (signifying  sulphur) 
on  the  slope  of  the  third  hill,  and  you  will  then  notice  a  little 
dot  marked  Se  (selenium)  and  another  Te  (tellurium)  in  a 
correspondingly  similar  position  on  the  other  two  hills  re- 
spectively. These  elements  have  strikingly  similar  proper- 
ties. Take  now  another  property  altogether,  let  us  say  the 


24 


THE   NEW  KNOWLEDGE. 


ATOMIC  VOLUMES 

8  £ 


Fig.  2. 


THE   ATOMS    OF  THE    ELEMENTS. 


25 


melting-point  of  the  elements,  and  make 
a  similar  diagram  (Fig.  3).  You  get 
a  curve  remarkably  like  the  first  one, 
with  this  exception,  that  the  elements 
which  were  at  the  top  of  the  first  curve 
are  now  at  the  bottom.  The  melting- 
point  curve  is  as  strictly  periodic  as  the 
volume  curve  and  of  the  same  general 
shape.  Notice  the  regular  irregularity 
of  the  two  curves,  and  notice  also,  if 
you  will,  that  there  is  not  only  a  peri- 
odicity but  a  double  periodicity,  as 
shown  in  the  little  hump  on  the  slope 
of  each  hill  of  the  curve.  Similar 
curves  may  be  constructed  for  many 
other  properties.  Can  we  imagine, 
then,  that  these  atoms,  these  little  in- 
visibilities, in  which  we  all  live  and 
move  and  have  our  being,  are  separately 
created,  arbitrarily  made,  unrelated  in- 
dividuals ?  Hardly  so,  for  they  are  ob- 
viously created  in  accordance  with 
some  scheme.  Would  that  we  might 
understand  this  scheme  all  and  in  all! 
It  would  be  a  veritable  glimpse  be- 
hind the  veil  of  existence.  But  if  we 
cannot  read  from  Alpha  to  Omega,  we 
may  spell  out  what  we  can,  leaving  fu- 
ture letters  for  future  men;  perforce 
content  that  if  in  this  cryptogram  of 
the  universe  we  know  indubitably  that 
there  is  a  cryptogram  to  be  read,  we 
have  at  least  come  to  the  beginnings  of 
knowledge. 


CHAPTER  III. 


THE  TABLE  OF  THE  LAW. 

This  periodicity  of  the  atoms  of  the  elements  and  the 
fact  that  they  exist  in  accordance  with  a  definite  scheme 
is  very  beautifully  shown  in  the  table  devised  by  Men- 
deleeff,  from  which  additional  hints  may  be  obtained.  For 
purposes  of  study  we  shall  first  consider  the  first  part  of 
the  Table  of  the  Law  as  originally  formed  by  Mendeleeff 
(Fig.  4). 


I 

II 

III 

IV 

V 

VI 

VII 

VIII 

1 

HI 

2 
3 

Li  7 

Be  9 

Bll 

C  12 

N14 

016 
S32 

Fl  19 
Cl  35.5 

Na23 

Mg24 

Al  27 

Si  28 

P31 

- 

4 

K39 

Ca  40 

Ti  48 

V51 

Cr  52 

Mn  55 

Fe  56,  Co  59, 
Ni59 

Fig.  l. 

ving  out  hydrogen  for  the  present  as  having  no  part 
in  the  scheme,  and  beginning  with  lithium,  you  will  observe 
that  if  we  arrange  the  succeeding  elements  in  the  order  of 
their  atomic  weights  up  to  fluorine,  that  the  next  or  eighth 
element,  sodium  (Na),  has  properties  similar  to  lithium. 
If,  then,  we  place  sodium  in  the  same  vertical  column  with 
lithium  and  then  arrange  the  next  elements  in  the  order  of 
their  atomic  weights,  we  observe  that  magnesium  falls  in 
(26) 


THE    TABLE    OF   THE    LAW.  27 

the  same  column  with  beryllium,  aluminum  with  boron, 
silicon  with  carbon,  phosphorus  with  nitrogen,  sulphur 
with  oxygen,  and  chlorine  with  fluorine, — all  of  them 
very  much  alike  in  their  properties,  in  pairs.  This  is,  of 
course,  sufficiently  remarkable,  but  let  us  begin  the  third 
line  with  the  next  element — potassium  (K).  It  falls 
straight  into  place  in  the  same  column  with  sodium  and 
lithium,  which  it  greatly  resembles ;  calcium  with  beryllium 
and  magnesium,  titanium  with  carbon  and  silicon,  vanadium 
with  nitrogen  and  phosphorus,  chromium  with  oxygen  and 
sulphur,  and  manganese  with  chlorine  and  fluorine.  Strik- 
ing analogies  again  appear  between  the  three  members  of 
each  group.  The  members  of  each  group  have  remarkably 
similar  properties.  We  now  see  in  this  scheme,  so  far,  a 
verification  of  the  Triads  of  Dobereiner,  for  the  three  ele- 
ments in  each  group  constitute  a  triad  of  the  kind  discov- 
ered by  him.  We  see,  also,  that  it  is  a  verification  of  the 
Octaves  of  Xewlands.  But  Xewlands,  as  we  shall  see,  had 
but  a  faintest  glimpse  of  the  sweep  of  this  bold  general- 
ization, which  laid  stress  not  only  on  the  fact  that  every 
eighth  element  resembled  the  first,  but  also  on  the  periodicity 
of  the  phenomenon.  In  order  to  grasp  the  meaning  of  this, 
let  us  notice  that  to  make  this  arrangement  true  and  valid, 
he  found  it  necessary  to  leave  a  blank  space  in  Group  3, 
Series  4,  for  some  element  hitherto  undiscovered, — and  not 
content  with  this,  he  proceeded  to  predict  the  properties 
it  should  possess  when  discovered! 

Here  is  the  full  Periodic  System  of  the  elements. as  it 
exists  to-day: 


28 


THE  NEW  KNOWLEDGE. 


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THE   TABLE   OF  THE   LAW.  29 

This  periodic  law  of  the  atoms  is  God's  alphabet  of  the 
universe.  By  means  of  it,  and  by  means  of  it  only,  can 
we  ever  hope  to  spell  out  the  history  and  the  future  of 
creation.  It  lies  here  before  us  lacking  only  the  master 
word — the  open  sesame — to  creation;  and,  who  knows,  to 
the  Creator,  too?  If  the  system  were  regular,  completely 
symmetrical,  we  should  either  understand  the  mystery— 
that  is,  there  would  be  an  end  of  the  mystery  altogether — 
or  we  should  forever  be  beyond  the  hope  of  solving  it.  But 
the  delight  of  it  is,  and  the  hope  of  it  lies  in  its  regular  irreg- 
ularity. Leaving  for  the  moment  the  whims  and  caprices  of 
the  law  that  constitute  its  irregularities,  let  us  turn,  first,  to 

THE    REGULARITIES    OF    THE    LAW. 

A  glance  at  the  table  (Fig.  5) -will  inform  the  reader  that 
each  of  the  elements  of  matter  has  a  little  compartment  of 
its  own  in  the  table.  This  compartment  belongs  to  it,  and 
the  element  will  refuse  to  go  anywhere  else. 

To  demonstrate  this,  we  may  fix  our  attention  upon  any 
one  element  and  consider  it  in  its  relation  to  the  other  ele- 
ments which  lie  either  m  ^horizontal  or  in  a  vertical  line  with  it. 

The  elements  which  lie  horizontally  with  reference  to  any 
given  element  are  called  a  series;  those  which  lie  vertically, 
a  group. 

The  actual  position  of  any  one  element  in  the  table  is  fixed 
solely  by  the  weight  of  its  atom ;  and  once  so  fixed,  its  other 
properties  follow  as  a  matter  of  necessity  from  its  series  and 
group  relations. 

The  elements  in  any  one  series  vary  by  definite  steps,  but 
they  are  sharply  differentiated  from  one  another;  and  in 
spite  of  their  progressive  variations  from  one  side  of  the 
table  to  the  other,  they  are  of  different  types.  The  ele- 
ments of  a  group  vary  progressively  from  top  to  bottom,  but 


30  THE   NEW  KNOWLEDGE. 

they  closely  resemble  one  another  and  are  distinctively  of 
the  same  type;  indeed,  we  may  go  further,  and  say  that  their 
relationship  is  so  pronounced  that  we  are  able  to  call  these 
groups  veritable  natural  families. 

As  an  example  of  such  group  relationship  let  us  consider 
the  elements  of  Group  II.  These  elements  are  in  the  order 
of  their  atomic  weight :  Beryllium,  magnesium,  calcium,  zinc, 
strontium,  cadmium,  barium,  mercury  and  radium.  Now,  in 
studying  these  elements,  the  curious  fact  crops  up  that  while 
all  the  elements  of  the  group  resemble  each  other  and  are  of 
the  same  blood,  so  to  speak,  they  may,  nevertheless,  be 
divided  into  two  sub-groups,  the  members  of  which  are 
peculiarly  like  each  other.  These  sub-groups  are: 

Sub-group  A.  Sub-group  B. 

Calcium  Beryllium 

Strontium  Magnesium 

Barium  Zinc 

Radium  Cadmium 

Mercury 

The  relations  between  the  two  sub-groups  may  fairly  be 
expressed  by  saying  that  calcium,  barium,  strontium 'and 
radium  are  sister  elements  and  bear  only  a  cousinly  relation- 
ship to  beryllium,  magnesium,  cadmium  and  mercury. 

The  curious  nature  of  this  double  relationship  in  a  group 
is  accentuated  by  the  fact  that  every  other  group  is  divided 
in  the  same  way  into  two  sub-groups  showing  similar  rela- 
tionships. Attention  has  been  drawn  already  to  a  double 
periodicity  in  the  curves  of  the  atomic  volumes  and  melting- 
points,  and  this  double  relationship  in  the  group  is  the  logical 
consequence  of  it.  How  clearly  related  in  their  properties 
these  sister  elements  are,  may  be  seen  in  the  subjoined 
table  (Fig.  6). 


THE   TABLE    OF   THE    LAW. 


31 


ELEMENT 

CALCIUM 

STRONTIUM 

BARIUM 

Atomic  Mass 

40 

88 

137 

Specific  Gravity 

1.6 

2.5 

3.6 

Carbonate  Dissociates; 
Temperature 

000°  C 

1100°  C. 

1400°  C. 

Grams  of  Hydroxide 
Soluble  in  a  Liter  of 
Water  at  15  °C 

1.32 

IS 

50 

Heat  of  Formation  of 
Chloride;  Units 

170 

185 

195 

Fig.  6. 

A  glance  at  this  table  shows  their  striking  similarity  of 
behaviour,  even  in  the  most  varied  properties.  This  simi- 
larity is  so  great  that  in  general  terms,  x  may  be  written, 
standing  for  either  calcium,  strontium  or  barium,  in  any 
chemical  reaction.  The  chief  purpose  of  the  diagram,  how- 
ever, is  to  show  that  even  as  they  vary  from  one  another, 
they  vary  progressively  and  in  definite  steps.  Notice  in  the 
diagram  that  as  the  atomic  weight  rises,  so  does  the  specific 
gravity,  the  temperature  at  which  their  carbonates  dissoci- 
ate, the  solubility  of  their  hydroxides,  and  the  heat  of  forma- 
tion of  their  chlorides. 

Suppose,  now,  we  take  another  group,  say  Group  VII, 
known  as  the  family  of  the  Halogens.  This  group  consists, 
as  usual,  of  two  sub-groups: 


Sub-group  A. 
Fluorine 
Chlorine 
Bromine 
Iodine 


Sub-group  B. 
Manganese 
Samarium 


THE   NEW  KNOWLEDGE. 


Concerning  Sub-group  A,  we  find  in  the  table  (Fig.  7) 
the  same  progressive  variation  in  steps. 


PROPERTIES 

FLUORINE 

CHLORINE 

BROMINE 

IODINE 

Atomic  Mass 

19 

35.5 

80 

127 

Boiling  Temperature 

-187°  C 

-33° 

+  59° 

4184° 

Specific  Gravity 

1.15  (liquid) 

1.5  (liquid) 

3.2  (liquid) 

5  (solid) 

Union  with  Hydro- 
gen takes  place 

In  the  dark 
at  ordinary 
tempera- 
tures 

In  sunlight 

At  red  heat 

At  red  heat, 
but  incom- 
pletely 

Heat  of  formation 
of  Hydrogen  Com- 
pound 

37.6 
heat  units 

22 

8 

-6.1 

Stability  of  Hydro- 
gen Compound 

Most  stable 

Decomposed 
at  1500  °C. 

Decomposed 
at  800°  C. 

Decomposed 
at  180°  C. 

Fig.  7. 

Thus,  if  fluorine  will  do  a  certain  thing,  chlorine  will  do 
it  more,  bromine  still  more,  and  iodine  most.  Or,  it  may 
act  the  other  way:  If  fluorine  does  a  certain  thing,  chlorine 
will  do  it  less,  bromine  still  less,  and  iodine  least  of  all.  The 
important  thing  is  that  as  the  elements  vary,  they  vary 
progressively  in  steps  as  the  atomic  weight  rises.  The  di- 
rection of  the  arrows  in  the  table  shows  the  direction  of  the 
progressive  change  for  each  property.  Now  what  holds  good 
for  Groups  II  and  VII  holds  equally  good  for  every  other 
group  of  the  system.  As  a  matter  of  fact,  the  elements  of 
matter  fall  naturally  into  a  series  of  groups.  Each  group 
falls  naturally  into  two  sub-groups,  which  have  in  certain 
properties  an  unmistakable  relation  to  each  other,  while  the 
constituent  members  of  each  sub-group  resemble  each  other 


THE    TABLE   OF  THE  LAW.  33 

to  an  extent  so  remarkable  that  in  general  terms  it  may  be 
said  that  what  one  will  do  the  others  will  do,  and  that  in 
their  very  differences  they  vary  progressively  in  definite 
steps.  Furthermore,  all  these  relations  are  true  because  of 
the  law  illustrated  in  the  curves  of  the  atomic  volumes  and 
melting-points,  that  the  properties  of  an  element  are  a 
periodic  function  of  its  atomic  weight. 
3 


CHAPTER  IV. 
THE  TESTING  OF  THE  LAW. 

When  once  the  weight  of  the  atom  of  an  element  is  known 
the  properties  of  the  element  are  fixed.  There  is  a  fatality 
about  it. 

How  true  this  is  may  be  aptly  illustrated.  Turn  to  the 
table  of  the  law  (Fig.  5)  and  note  in  Group  III  the  third 
and  fourth  elements,  Sc  (Scandium)  and  Ga  (Gallium),  and 
in  the  fourth  group  the  fourth  element  Ge  (Germanium). 
When  Mendeleeif  enunciated  his  law  and  made  his  table 
originally,  he  found  it  necessary,  in  order  to  make  the  table 
true,  to  leave  these  three  spaces  vacant  for  undiscovered 
elements,  and,  not  content  with  this,  he  proceeded  in  1871, 
on  the  basis  of  the  law,  to  predict  the  properties  which  these 
elements  should  possess  when  discovered. 

Think  of  the  presumption  of  it,  that  out  of  the  seventy-  * 
eight  odd  substances  of  which  God  had  made  his  universe, 
three  were  missing  !  And  that  these  three  possessed  proper- 
ties which  he  proceeded  to  specify  with  extreme  minute- 
ness. These  three  hypothetical  elements  he  named  eka- 
boron,  eka-aluminum,  and  eka-silicon,  "little  imagining," 
as  he  says  himself,  "that  he  would  live  to  see  the  verifica- 
tion of  his  predictions." 

But  so  it  was;  for  out  of  the  night  of  the  unknown,  one 
after  another  came  to  meet  him.  One  from  the  hills  of 
Scandinavia,  another  from  the  Pyrenees  of  France  and 
a  third  from  the  mines  of  Germany.  The  three  elements 
were  named  scandium,  gallium  and  germanium,  and  they  are 
(34) 


THE   TESTING    OF   THE    LAW.  35 

not  only  very  like  but  they  actually  are  the  predicted  ele- 
ments eka-boron,  eka-aluminum  and  eka-silicon  respec- 
tively. How  unquestionable  this  fact  is  may  be  readily 
seen  from,  for  example,  a  comparison  of  MendeleerT's  eka- 
boron  with  the  scandium  afterwards  discovered  by  Nilson. 

Eka-boron .  Scandium. 

Atomic  weight  44.  Atomic  weight  44. 

Oxide  EbA.  Oxide  Sc,03- 

Sulphate  less  soluble  than      Sulphate  less  soluble  than 
aluminum  sulphate.  aluminum  sulphate. 

Carbonate  insoluble  in  water.  Carbonate  insoluble  in  water. 

Salts  colorless  and  form  ge-  Salts  colorless  and  form  ge- 
latinous precipitates  with  latinous  precipitates  with 
potash  and  ammonia.  potash  and  ammonia. 

The  predicted  properties  are  identical  with  the  properties 
found.  The  hypothetical  element  discovers  itself  in  scan- 
dium. 

In  like  manner  the  other  two  elements  discovered  them- 
selves in  gallium  and  germanium.  We  see  in  this  success- 
ful three-fold  prediction  the  scope  and  power  of  the  periodic 
law  as  an  instrument  of  research.  We  see  convincingly 
that  the  law  must  be  the  expression  of  a  fact.  Suppose 
that  an  astrologer  informed  you  that  your  horoscope  led 
him  to  believe  that  you  would  meet,  sometime  in  your  life, 
three  men;  and  that  with  the  utmost  particularity  he  told 
you  their  weights,  the  color  of  their  hair,  the  size  of  their 
noses,  and,  in  a  word,  all  the  habits  of  .mind  and  body  suffi- 
cient to  differentiate  them  positively  from  all  other  men;  and 
suppose,  moreover,  that  you  met  these  men  possessed  of 
qualities  identical  with  the  description  predicted.  You 
would  believe  in  astrology. 

Astrology   cannot  do   these   things,  but   chemistry  can 


36  THE   NEW  KNOWLEDGE. 

because  of  the  periodic  law.  Therefore  we  believe  in  the 
periodic  law.  We  believe  that  the  weight  of  the  atom 
of  the  element  fixes  its  properties  and  its  position  in  a 
great  scheme  of  relationship.  You  will  find  many  blank 
spaces  still  in  the  table  of  the  law  ready  for  elements  yet 
in  the  womb  of  the  future.  So  thoroughly  does  the  chem- 
ist believe  in  this  law  that  he  has  not  hesitated  in  several 
instances  to  put  certain  " refractory"  elements  "in  their 
places."  Thus,  indium,  beryllium  and  uranium  would  not 
fit  properly  into  their  proper  compartments  in  the  table 
on  the  basis  of  the  old  determinations  of  the  atomic 
weights.  Renewed  investigation,  however,  showed  the  er- 
rors of  these  old  determinations,  and  the  new  atomic 
weights,  accurately  adjusted,  allowed  them  to  fall  straight 
into  the  positions  to  which  they  naturally  belong  in  the 
table,  and  which  they  hold  to-day. 

One  concluding  and  conclusive  test  of  the  validity  of  the 
law  was  found  in  the  discovery  of  the  rare  gases  of  the 
atmosphere  by  Lord  Rayleigh  and  Sir  William  Ramsay. 
The  history  of  their  discovery  is  interesting.  In  1893  Lord 
Rayleigh  undertook  to  determine  the  density  of  nitrogen  with 
all  the  accuracy  of  present-day  science.  To  his  astonish- 
ment, he  discovered  that  nitrogen  from  the  air  and  nitrogen~f 
from  chemical  compounds  did  not  weigh  the  same.  The  dif- 
ference was  small  but  exasperatingly  constant.  Out  of  this 
curious  anomaly  arose  the  discovery  of  a  new  and  hitherto 
unsuspected  element  of  the  air  which  had  been  weighed  as 
nitrogen  and  considered  as  nitrogen  by  all  preceding  chem- 
ists. This  new  element  was  named  argon  and  it  constitutes 
nearly  one  per  cent,  of  the  air  we  breathe.  Subsequently 
this  "argon"  was  discovered  to  be  itself  impure,  and 
from  it  were  isolated  four  other  elements,  helium,  neon, 
krypton  and  xenon.  These  five  new  elements  are  all 


THE    TESTING   OF   THE    LAW.  37 

alike  in  this:  that  they  differ  from  all  other  elements  in 
having  no  combining  power  whatever.  It  has  been  found  im- 
possible to  make  them  unite  chemically  with  any  other 
substance  in  nature.  They  thus  constituted  a  new  and 
separate  family  of  elements  for  which  there  seemed  to  be 
no  place  in  the  periodic  law.  Now  the  law  undertakes  to 
find  a  place  for  any  and  every  element  in  nature.  The 
validity  of  the  law  was  threatened.  The  case  was  serious. 
Let  us  see  how  neatly  and  completely  the  law  was  vin- 
dicated. One  of  the  most  curious  facts  in  connection  with 
the  periodic  law  is  the  regular  increase  in  the  valence  of 
the  Groups.  By  valence  is  meant  the  power  of  an  atom 
to  unite  chemically  with  other  atoms,  in  other  words  "  the 
grabbing-power  "  of  the  atom.  If  we  consider  these  val- 
ences, for  the  present,  as  so  many  little  arms  to  hold  on 
with,  we  find  that  the  elements  of  the  different  groups, 
from  Group  I  to  Group  VIII,  have  1,  2,  3,  4,  5,  6,  7  and  8 
arms  respectively.  This  variation  in  the  "  grabbing-power  " 
is  well  exemplified  in  the  way  in  which  the  atoms  in  (let  us 
say)  Series  3  unite  with  fluorine  to  form  fluorides : 


1  atoi 
1 
1 

n  of  sodium  unites 
magnesium 

aluminum 

with  1  atom  of   fluorine  to  form 

1  molecule  of  f 

3 

1              M             •<              < 

1 

silicon 

'         4 

i              (1              II              < 

"        "        ' 

1 
1 

phosphorus 
sulphur 

1         5 
'         6 

'              "              "        '      ' 

II                 U                 « 

—while  the  element  chlorine  does  not  unite  with  fluorine  at 
all,  owing  apparently  to  the  fact  that  they  both  belong  to 
the  same  family,  are  alike  in  their  nature,  and  are,  so  to 
speak,  sister  elements. 

Now  these  five  new  elements,  helium,  neon,  argon,  kryp- 
ton and  xenon,  have  no  combining  power  whatever,  no 
arms  at  all,  so  to  speak;  hence  they  should  constitute  a 
separate  group  coming  before  Group  I,  the  members  of  which 


38 


THE   NEW   KNOWLEDGE. 


have  one.  But  will  they  fit  into  such  a  position?  Indeed 
they  will;  their  atomic  weights  thrust  them  naturally  and 
inevitably  into  that  very  place,  thus : 


SERIES 

ZERO  GROUP 

GROUP  I 

2 

Helium  4.0 

Lithium  7.03 

3 

Neon  19.9 

Sodium  23.05 

4 

Argon  38 

Potassium  39.1 

5 

Copper  63.6 

6 

Krypton  81.8 

Rubidium  85.4 

7 

Silver  107.9 

8 

Xenon  128 

Caesium  132.9 

9 

10 

The  law,  therefore,  which  seemed  at  first  assailed,  was 
amply  capable  of  taking  care  of  itself,  and  the  new  and  in- 
teresting family  in  the  commonwealth  of  the  elements  finds  a 
fitting  home  in  the  Zero  Group  of  Mcndeleerf  s  latest  table 
(Fig.  5). 

As  an  extra-conclusive  and  final  test  of  the  law,  look  at 
the  space  in  Group  2,  Series  12,  in  this  same  figure  (Fig.  5). 
Wonderful  as  that  element  is,  and  much  as  we  shall  have  to 
speak  of  it  in  succeeding  pages,  its  atomic  weight  leads  it 
inevitably  into  its  proper  place  in  this  system  of  the  ele- 
ments, directly  under  barium,  of  which  in  its  chemical 
properties  it  is  a  sister. 


CHAPTER  V. 
THE  SIGNIFICANCE  OF  THE  LAW. 

In  the  foregoing  pages  we  have  been  confronted  with  a 
series  of  extraordinary  facts  concerning  the  atoms  of  the  ele- 
ments of  matter  and  it  now  behooves  us  to  seek  earnestly 
for  the  cause  of  it  all. 

The  remarkable  approximation  to  regularity  in  the  atomic 
weights,  as  observed  in  Prout's  Law,  the  Triads  of  Do- 
bereiner,  the  Octaves  of  Newlands,  and,  finally,  the  summa- 
tion of  the  mystery  in  the  Periodic  Law  makes  a  most 
impressive  demonstration  of  a  scheme  of  arrangement 
among  the  atoms.  No  such  scheme  could  be  the  result  of 
mere  chance  on  the  basis  of  the  theory  of  probability.  This 
scheme  of  arrangement  must  mean  something,  and  this 
something  must  be  fundamentally  important. 

The  main  characteristic  of  the  whole  scheme  is  relation- 
ship. The  elements  are  unquestionably  not  fragmentary, 
unrelated  facts  in  nature.  They  are  related  to  one  another 
in  a  very  real  sense ;  and  it  is  an  expression  of  this  relation- 
ship that  we  must  seek  in  the  meaning  of  the  law.  We 
may  begin  either  by  assuming  that  the  atoms  are  simple, 
undecomposable,  separately  created,  ultimate  things,  or 
that  they  are  not.  There  is  no  tertium  quid.  If  the  atoms 
are  in  fact  ultimates,  then  you  will  seek  in  vain  for  any  ex- 
planation of  the  foregoing  mystery.  There  positively  is  no 
conceivable  explanation. 

If,  on  the  contrary,  you  assume  that  they  are  made  up  of 

(39) 


40  THE   NEW  KNOWLEDGE. 

parts,  then  the  fact  of  relationship  may  be  explained  in  a 
simple,  rational  manner. 

For  if  the  atoms  are  not  simple,  but  on  the  contrary  are 
made  up  of  component  parts,  then  these  parts  would,  of 
course,  unite  together  in  certain  numbers  and  in  certain 
ways  to  constitute  the  composite  bodies  we  call  atoms; 
just  as  the  atoms  unite  in  various  numbers  and  in  various 
ways  to  constitute  the  molecules  of  compounds,  and  it  is 
reasonable  to  assume  that  they  actually  would  do  so.  Thus, 
among  the  compounds  of  carbon,  we  are  acquainted  with 
series  of  compounds,  which  in  variations  of  molecular  weight 
and  gradation  of  properties  bear  a  striking  resemblance  to 
the  elements  when  arranged  after  the  fashion  of  the 
Groups  in  the  periodic  law.  For  example,  we  have  the 
series: 

ftlolecular  weight. 

CH4  Methane  16 

C2H6  Ethane  30 

C3H8  Propane  44 

C4H10  Butane  58 

C5H12  Pentane  72 

and  a  list  of  others  up  to  a  compound  of  the  formula 
Cy^  in  which,  with  a  regular  *  crease  of  14  in  the 
molecular  weight,  there  is  a  regular  variation  in  their  prop- 
erties in  such  a  way  as  to  constitute  th«  .1  a  definite  group. 
Therefore,  if  groups  of  atoms  may  unite  together  to  form 
bodies  with  correlated  properties  and  group  relationships, 
why  should  not  groups  of  sub-atoms  unite  together  to  form 
the  atoms  with  similar  group  relationships  ?  Again,  in 
chemistry,  we  occasionally  find  little  groups  of  atoms 
actually  playing  the  role  of  elements.  Thus,  the  little 


THE   SIGNIFICANCE   OF  THE   LAW.  41 

group  NH4,  known  as  the  ammonium  group,  will  pass 
from  compound  to  compound  maintaining  its  integrity  and 
behaving  marvellously  like  the  element  potassium  or  sodium. 
We  see,  therefore,  that  groups  of  atoms  may  simulate  the 
elements  of  matter,  and  we  see,  moreover,  that  the  scheme 
of  relationship  and  periodicity  of  properties,  unquestionably 
evident  in  the  elements,  finds  a  reasonable  and  natural  ex- 
planation in  the  assumption  that  the  atoms  of  the  elements 
are  made  up  of  sub-atoms,  which  act  in  the  atom  just  as 
the  atoms  act  in  the  molecule.  It  is  all  natural,  reason- 
able and,  indeed,  inevitable.  One  thing  is  needed,  the  ex- 
istence of  a  body  smaller  than  an  atom,  and  it  will  be  one 
important  business  of  our  book  to  seek  and  find  this  thing. 
But  the  bare  fact  of  sub-atomicity  is  not  the  only  secret  of 
the  periodic  law.  We  have  spoken  not  only  of  gradation 
of  properties,  but  of  similarity  and  relationship.  We  have 
spoken  of  the  elements  as  sisters  2  d  cousins;  in  other 
words,  of  a  real  relationship,  not  an  analogous  one.  If  we 
may  speak  of  sisters  and  cousins,  why  not  of  fathers  and 
mothers,  and  even  grandfathers  ?  Throughout  all  biological 
science  family  relationship  is  taken  indubitably  to  mean 
common  origin.  Evolution  is  based  on  this  assumption. 
AVhenever  the  biologist  finds  a  series  of  organisms,  vegetable 
or  animal,  betraying  in  their  structure  manifold  likeness 
of  form,  he  says  at  on^e:  "  These  organisms  have  had  a 
common  ancestry;  they  have  been  evolved,  all  of  them, 
from  some  one  simpler  form."  Now  it  is  this  very  form 
of  argument  that  takes  us  inevitably  to  the  conclusion  that 
the  atomic  families,  themselves,  since  they  show  family  re- 
lationships as  sharply  defined  as  any  to  be  found  in  biology, 
are  of  common  origin  and  descent,  and  that  the  atoms,  as 
we  know  them,  are  the  product  of  an  evolution — an  in- 
organic evolution.  It  will  be  another  important  part  of  the 


42  THE   NEW   KNOWLEDGE. 

business  of  our  book  to  seek  and  find  the  sufficient  evidence 
of  the  evolution  of  the  atoms. 

So  far  as  we  have  gone,  our  conclusions  do  not  rest  on 
positive  or  absolutely  demonstrative  evidence.  It  is  pre- 
sumptive evidence,  the  simple  fact  being  that,  with  these 
two  foregoing  conclusions  taken  as  assumptions,  things  are 
explained;  not  taken  as  assumptions,  nothing  is  or  can  be 
explained. 


PART  III. 


GASEOUS   IONS. 


PART  III. 
GASEOUS  IONS. 


CHAPTER  I. 

GASES  FROM  THE  STANDPOINT  OF  PHYSICS:  How  THEY 
CONDUCT  ELECTRICITY. 

In  the  foregoing  pages  an  attempt  has  been  made  to 
show  above  everything  else  the  necessity  of  finding  some 
one  thing  to  explain  our  explanations.  We  have  learned 
that  there  is  a  strange  law  that  binds  together  the  diverse 
elements  of  matter;  and  this  law  has  led  us  to  the  very 
reasonable  conclusion  that  the  atoms  of  matter  are  com- 
posite particles,  built  up  of  particles  smaller  still,  and  that 
the  atoms,  as  we  know  them,  have  probably  undergone 
some  form  of  evolution  from  simpler  conditions. 

But  we  have  no  positive  proof  of  this.  It  is  simply  a 
reasonable  hypothesis,  based  upon  observed  facts;  and, 
moreover,  even  if  we  actually  had  this  proof  we  should 
not  be  able  to  explain  the  meaning  of  the  periodic  law 
and  the  mystery  of  matter.  The  One  Thing  is  missing; 
and  while  the  chemist  may  tell  us  of  a  certain  search  he 
has,  he  cannot  give  us  the  actual  touchstone  of  truth  that 
we  demand.  We  must,  therefore,  abandon  the  chemist 
to  his  retorts  and  crucibles,  his  burettes  and  condensers, 
and  betake  ourselves  elsewhere.  Preferably,  we  should  go 
to  the  laboratory  of  the  physicist. 

(45) 


46  THE   NEW  KNOWLEDGE. 

Here,  we  are  in  another  world.  Instruments  of  infinite 
precision  surround  us,  optical,  electrical  and  magnetic,  and 
the  whole  atmosphere  of  the  place  tingles  with  accuracy. 
Things  are  the  subject  of  investigation,  to  be  sure,  as  they 
are  in  the  chemical  laboratory,  but  they  are  looked  at  in  a 
different  way.  The  subject  of  the  atom  is  as  interesting 
to  the  physicist  as  it  is  to  the  chemist;  but  the  method  of 
attack  is  different. 

As  a  good  example  of  this  difference  of  method,  consider 
the  subject  of  gases,  with  which  we  must  now  occupy  our- 
selves in  order  to  discover  the  first  clue  to  the  One  Thing 
which  is  the  object  of  our  search.  The  chemist,  of  course, 
considers  mainly  the  chemical  properties  of  gases,  their 
action  on  other  bodies  and  the  products  of  the  action.  The 
physicist,  on  the  contrary,  considers  primarily  the  physical 
properties  of  gases;  to  him  the  particular  gas  involved  is 
more  or  less  a  matter  of  indifference,  for  in  their  physical 
properties  all  gases  are  wonderfully  alike:  which  is  very 
readily  shown  in  the  very  similar  manner  in  which  they  ex- 
pand and  contract  under  the  influence  of  pressure  and  heat. 

The  physical  property  with  which  we  are  most  con- 
cerned in  our  search  is  the  electrical  conductivity  of  a  gas. 
All  gases  in  the  normal  state  conduct  electricity  to  a  slight, 
but  only  to  a  very  slight,  degree.  If  the  air,  for  example, 
were  to  any  marked  degree  a  conductor,  it  is  obvious  that 
telegraph  wires  would  be  impossible,  for  the  electricity 
would  leak  away.  The  air,  however,  does  possess  a  very 
slight  conductivity;  and  this  may  easily  be  demonstrated 
by  a  little  instrument  known  as  the  electroscope. 

The  electroscope  may  be  made  by  attaching  a  thin  strip 
of  gold  leaf  to  a  vertical,  insulated  brass  plate.  If  the  gold 
leaf  and  brass  plate  be  electrified,  the  repulsive  force  be- 
tween the  portions  of  the  same  charge  causes  the  gold  leaf 


GASES    FROM    THE    STANDPOINT    OF   PHYSICS.  47 

to  stand  out  at  an  angle  which  measures  the  amount  of 
electrification.  Experience  always  shows  that  the  charge 
leaks  gradually  away,  Fig.  8,  and  the  gold  leaf  falls  slowly 
down  to  the  brass  plate.  So  small,  however,  is 
this  leakage  that  physicists  have  from  time  to 
time  refused  to  believe  that  the  air  or  sur- 
rounding  gas  had  conducted  it  away  of  itself, 
and  have  ascribed  the  leakage  either  to  defect- 
ive insulation  or  to  the  presence  of  dust  parti- 
cles in  the  gas  concerned.  Nowadays  we  know 
positively  that  such  leakage  does  really  occur 
through  air  or  any  normal  gas,  and  that,  con-  scope.) 
sequently,  we  must  call  a  gas,  to  that  extent,  at  AC.  Brass 

least,  a  conductor. 

T  ^-     v  i  j.   i     j.  •    i         i       •       B-  Gold  Leaf. 

In  many  ways  this  slight  electrical  conductiv-  ^/  HC  \     \n_ 

ity  of  a  gas  may  be  increased.  Gases  become  gle  of  Electri- 
conductible,  for  instance,  (1)  when  they  are  fixation, 
heated  up  to  a  certain  point,  or  when  they  are  drawn  from 
the  neighbourhood  of  flames  or  an  electric  arc;  (2)  when 
they  have  recently  been  in  contact  with  glowing  metals  or 
carbon ;  and  (3)  when  they  have  diffused  through  a  space 
through  which  an  electric  discharge  is  passing  or  has  passed. 
Again  (4),  a  gas  becomes  conductible  when  X-rays  pass 
through  it,  or  (5)  cathode  rays.  Further  (6),  tri3  m:-iv 
presence  of  certain  substances  is  sufficient  to  cause  this  con- 
ductivity— substances  such  as  the  compounds  of  uranium, 
thorium,  radium,  polonium  and  actinium.  And,  finally  (7), 
gases  become  conductors  under  the  influence  of  ultra-violet 
light,  or  (8)  when  they  are  passed  over  molten  phosphorus 
or  bubbled  through  water. 

Having,  now,  learned  so  much  of  the  electrical  conductiv- 
ity cf  gases,  we  must  proceed,  in  another  chapter,  to  dis- 
cover where  this  knowledge  leads  us  in  our  search. 


CHAPTER  II. 
DISCOVERY  OF  IONS:  A  NEW  KIND  OF  PARTICLES. 

The  fact  that  gases  ordinarily  possess  but  a  slight  elec- 
trical conductivity  may  not  seem  particularly  impressive,  or 
even  the  additional  fact  that  this  conductivity  may  be 
vastly  increased,  until,  indeed,  they  become  very  good  con- 
ductors. Yet  this  simple-seeming  fact  is  destined  above 
all  others  to  inform  man  of  some  of  nature's  most  carefully 
guarded  knowledge.  Some  facts,  it  may  be  observed,  are 
pregnant  with  the  meaning  of  a  universe;  and  this  is  one 
of  them. 

Starting,  then,  with  this  apparently  unimportant  fact,  we 
may  best  begin  our  study  with  a  candle  flame.  Bring  the 
candle  up  to  the  little  charged  electroscope.  Observe  that 
the  leaves  collapse,  verifying  the  fact  previously  stated ,  that 
the  gas  in  the  neighbourhood  of  a  flame  is  a  conductor  of 
electricity.  Knowing  this,  it  is  important  to  find  out  why. 
And  we  discover  the  why  in  the  properties  of  the  conducting 
gas. 

In  the  first  place,  the  gases  which  come  from  the  flame 
retain  tJieir  conductivity,  even  after  they  have  got  some  dis- 
tance away  and  have  been  cooled  by  the  surrounding  air. 
It  has  been  proved  that  such  a  gas  will  retain  some  con- 
ductivity six  or  seven  minutes  after  it  has  loft  the  flame. 
Fig.  9.  You  may  prove  it  for  yourself  by  drawing  the 
gas  from  the  flame  over  the  leaves  of  the  electroscope 
situated  at  some  dislanc",  under  which  conditions  the 
leaves  collapse,  thus  showing  that  the  gas  retains  its 
(48) 


DISCOVERY  01    i 


40 


conductivity  for  the  time  taken  by  it  to  travel  from  the 
flame  all  the  way  to  the  electroscope. 

We  may  now  suppose  ourselves  seeking  help  from  the 
chemist.  "  Why,"  he  will  say,  "  the  gas  from  the  flame 
contains  nothing  but  carbonic  acid  and  water.  There  is 
nothing  remarkable  in  such  things." 

"Very  true,"  we  say;  "  but  it  contains  conduct irily." 

"Conductivity  is  a  condition,"  he  will  reply,  "not  a 
thing." 

But  are  we  sure  of  that  ?  Let  us  filter  the  gas  from  the 
flame  through  a  wad  of  glass  wool  before  it  arrives  at  the 


To  Pump 


Fig.  9.     Apparatus  for  showing  that  the  air  retains  its  conductivity. 

electroscope,  or  let  us  bubble  it  through  water,  instead.  If 
this  be  done  very  carefully,  the  astonishing  result  be- 
comes evident  that  every  trace  of  conductivity  is  re- 
moved !  And  pursuing  our  experimentation,  we  discover 
that  the  conductivity  may  be  removed,  us  well,  by  mak- 
ing the  gas  traverse  a  space  through  which  a  current  of 
electricity  is  passing. 

The  explanation,  then,  is  clear.  The  conductivity  can- 
not be  a  mere  condition.  If  we  can  blow  the  conducting 
air  about  from  one  place  to  another,  and  if,  moreover,  we 
can  filter  it  free  from  conductivity  by  passing  it  through 
wool  or  bubbling  it  through  water,  it  is  obvious  enough 
4 


50  THE   NEW  KNOWLEDGE. 

that  this  conductivity  must  be  due  to  an  actual  some- 
thing mixed  with  the  gas,  this  something  being  removed 
by  filtration. 

It  is  also  obvious  that  this  something — since  the  gas  is 
perfectly  transparent — must  be  in  the  nature  of  particles, 
and  that  these  particles,  which,  it  must  be  remembered, 
are  conducting  particles,  must  be  different  from  the  par- 
ticles, or  molecules,  of  the  gas  in  the  normal  state.  The 
further  fact  that  these  particles  may  be  removed  by  mak- 
ing the  conducting  gas  traverse  a  space  through  which  a 
current  of  electricity  is  passing  shows  that  the  particles 
must  be  electrified;  and  since,  moreover,  the  conducting 
gas  as  a  whole  shows  no  charge  that  these  particles  must 
be"  both  positive  and  negative.  This  latter  fact  is  also 
shown  in  Fig.  10,  which  illustrates  the  division  of  a  flame 


Fig.  10.     Showing  the  division  of  a  flame  into  two  parts  by  placing 
it  between  oppositely  charged  plates. 

into  two  parts,  one  part  positively  and  the  other  nega- 
tively electrified,  simply  by  placing  the  flame  between  two 
oppositely  charged  plates. 

AYe  have  been  led,  then,  to  the  di.-covery  of  certain  elec- 
trified particles  in  the  conducting  pis.  These  particles  are 
called  ions,  and  the  process  by  which  the  gas  is  made  into 
a  conductor,  the  ionisation  of  the  gas. 


CHAPTER   III. 
DISCOVERY  OF  CORPUSCLES. 

With  the  discovery  of  gaseous  ions,  we  have  evidently 
lighted  upon  a  new  kind  of  particles  about  which  nothing 
is  said  in  the  chemistries;  and,  of  course,  the  questions 
immediately  arise:  What  are  these  ions?  Do  they  exist 
only  in  gases?  Are  they  molecules,  or  atoms,  or,  what  is 
most  important  to  us,  are  they  less  than  atoms?  What  is 
the  meaning  of  their  electrical  qualities?  We  may  best  an- 
swer these  questions  by  considering,  now,  the  ionisation 
produced  by  glowing  metals  or  by  carbon. 

The  effect  of  this  agency  may  readily  be  shown  by  means 
of  the  apparatus  shown  in  Fig.  11.  It  is  a  glass  vessel  con- 


To  Electrometer 


Battery 


Battery 


Fig.  11.     Apparatus  for  studying  the  ions  from  a  hot  wire. 

(51) 


52  THE    NEW   KNOWLEDGE. 

taining  an  insulated  metal  plate,  A,  which  is  in  connection 
with  an  electrometer;  underneath  this  plate  there  is  a 
fine  metallic  wire,  which  can  easily  be  raised  to  incandes- 
cence by  an  electric  current  passing  through  it  from  C  to 
D.  Taking,  first,  the  case  in  which  the  air  within  the  ves- 
sel is  at  the  ordinary  pressure  of  the  atmosphere,  it  will 
be  observed  that,  as  the  wire  grows  hotter  and  hotter,  un- 
til it  just  begins  to  glow,  the  metal  plate  receives  a  charge 
of  electricity,  and,  furthermore,  that  this  charge  is  posi- 
tive. It  will  next  be  observed  that  this  charge  steadily  grows, 
until  the  wire  is  at  a  yellow  heat,  when  it  is  at  a  maxi- 
mum; and  that,  after  passing  this  stage,  it  diminishes  rap- 
idly with  the  increasing  temperature  of  the  wire,  until, 
when  the  wire  reaches  a  bright  white  heat,  the  charge  re- 
ceived by  the  plate  is  very  small. 

So  far,  we  learn  that  not  only  may  a  hot  wire  as  well 
as  a  candle  flame  constitute  an  electric  battery,  but  that 
these  gaseous  ions,  which  pass  from  the  wire  to  the  plate, 
need  not  necessarily  convey  both  kinds  of  electricity,  but 
may  convey  one  kind  only,  that  kind  being  positive.  At 
this  stage  of  the  experiment,  then,  and  while  the  wire  is 
still  hot,  pump  out  the  air  within  the  vessel,  which,  it  must 
be  remembered,  has  so  far  been  at  the  pressure  of  the 
atmosphere.  At  first,  little  change  will  be  noticed  in  the 
positive  charge  upon  the  metal  plate ;  but  as  the  exhaustion 
proceeds,  at  a  certain  point,  depending  upon  the  tempera- 
ture of  the  wire,  the  sign  of  the  electricity  upon  the  plate 
changes.  It  is  now  negative,  not  positive;  and  when  almost 
all  the  air — but  not  quite  all — has  been  pumped  out  of  the 

•1,  this  negative  charge  may  reach  a  high  value. 
\Ve  Irani  by  this  that   the  gaseous  ions  comprise  particles 
of  two  kinds,  one  carrying  positive  electricity  and  the  other 

•ive;  and  we  are  now  in  a  position  to  understand  why 


DISCOVERY   OF  CORPUSCLES.  53 

the  positive  charge  on  the  plate  decreased  as  the  tempera- 
ture rose  above  a  certain  point.  It  was  obviously  because 
at  a  certain  temperature  negative  particles  began  to  be 
evolved  as  well  as  positive,  and  that,  flying  side  by  side 
with  the  positive  particles  from  the  wire  to  the  plate,  they 
tended  to  neutralize  their  effect.  Thus,  a  low  temperature 
and  a  high  pressure  are  favorable  to  the  production  of  posi- 
tive ions;  and,  conversely,  a  high  temperature  and  a  low 
pressure  are  favorable  to  the  production  of  negative  ions. 

These  negative  particles,  or  ions,  owing  to  the  impor- 
tance they  have  developed,  are  given  a  special  name.  They 
are  called  corpuscles. 


CHAPTER  IV. 
FACTORS  OF  A  CORPUSCLE:  AN  EXPERIMENT. 

Concerning  corpuscles,  we  have  so  far  found  that  they 
ire  little  bodies,  laden  with  negative  electricity,  dancing  off 
rom  glowing  metals,  incandescent  carbon  or  gas  flames; 
ind  we  have  now  a  very  reasonable  curiosity  to  know 
1)  how  fast  they  travel,  (2)  what  electric  charge  they 
:arry,  and  (3)  what  they  weigh.  If  we  but  knew  these 
hree  elements,  we  may  be  sure  we  should  know  the  corpus- 
les  fairly  well,  so  far  as  their  extrinsic  qualities  go.  Arid, 
f  our  search  is  to  continue,  it  is  to  the  discovery  of  these 
lements  that  we  must  now  proceed. 

These  values  are  readily  determinable  for  corpuscles  as 
hey  fly  off  from  hot  metals,  but  it  may  be  more  convenient 
o  derive  them,  here,  for  corpuscles  emitted  by  metals  under 
he  impact  of  ultra-violet  light.  We  are  already  acquainted 
nth  the  fact  that  glowing  metals  give  off  negatively  <  ler- 
rified  particles,  or  corpuscles;  but  it  is  an  entirely  IK  w 
tatement  to  say  that  metals,  without  the  application  of 
ny  heat  whatever,  will  give  out  these  same  corpuscles  on 
Oere  exposure  to  light.  But  the  fact  is  without  difficulty 
lemonstrated  by  charging  a  newly  cleaned  surface  of  zinc 
nth  electricity,  and  exposing  it  to  the  light  from  an  arc 
amp;  for  the  zinc  plate  rapidly  loses  its  elrrtrifirat  ion,  and, 
easoning  anologous  to  that  previously  applied,  leads  irre- 
i-tihly  to  the  conclusion  that  the  loss  is  occasioned  by  oor- 
mscles  flying  away  with  it. 

It  turns  out,  however,  that  the  active  constituent  of  the 
(54) 


FACTORS   OF  A  CORPUSCLE.  55 

light  that  causes  this  corpuscular  migration  is  the  ultra- 
vioht  waves — that  is,  waves  that  are  too  short  to  cause  the 
sensation  of  sight  to  the  eye,  and  which,  on  dispersing  the 
light  through  a  prism,  lie  beyond  the  violet  end  of  the  spec- 
trum. Thess  ultra-violet  light  waves,  though  they  do  not 
affect  the  eye,  are  nevertheless  for  the  most  part  the  active 
agents  in  affecting  the  sansitive  plate  of  a  camera,  or  in 
tanning  the  skin.  Sunlight  is  not  rich  in  them,  for  the  at- 
mosphere absorbs  them ;  but  a  copious  supply  is  found  in 
the  light  obtained  from  an  arc  lamp,  or  by  burning  magne- 
sium wire,  or  by  sparking  with  an  induction  coil  between  zinc 
or  cadmium  terminals. 

Our  task  is  to  weigh  and  to  determine  the  motion  of  and 
the  charge  on  the  corpuscles  as  they  fly  off  from  a  metal 
plate  under  the  incidence  of  ultra-violet  light.  This  is 
done  by  means  of  an  apparatus  shown  in  Fig.  12.  A  is 
a  charged  aluminum  plate  on  which  the  ultra-violet  light 
shines;  this  light  comes  from  a  spark  between  zinc  termi- 
nals connected  with  an  induction  coil,  and  enters  the  tube 
through  the  quartz  window,  B,  which  is  peculiarly  trans- 
parent to  ultra-violet  waves.  E  is  another  metal  elec- 
trode, perforated  in  the  middle.  It  shields  the  right-hand 
part  of  the  apparatus  from  the  electrified  plate,  A,  and 
provides  a  window  through  which  the  corpuscles  may  fly 
into  the  right-hand  chamber.  D  and  (7  are  little  metallic 
plates  that  can  be  connected  with  an  electrometer. 

All  this  apparatus  is  enclosed  in  a  sealed  glass  vessel  from 
which  the  air  has  been  almost  altogether -exhausted  by  pump- 
ing. On  sending  the  ultra-violet  light  through  the  quartz 
window,  B,  so  that  it  falls  on  the  charged  aluminum  plate, 
A,  corpuscles  fly  off  from  A  at  right  angles  to  it,  and,  pass- 
iiig  in  a  beam  through  the  window  of  the  screen,  E,  they 
strike  the  metal  plate;  D,  give  up  their  electricity  to  it  and 


56 


THE   NEW   KNOWLEDGE. 


signify  their  presence  in  the  electrometer  in  connection  with 
it. 

So  far,  so  good.  But  how  does  this  help  us  to  the  weight 
and  velocity  of  the  corpuscles  ?  Let  us  see.  The  first  thing 
we  notice  is  that  while  the  electrometer,  or  measurer  of  elec- 
trification, connected  with  the  plate,  D,  is  charged  on  the  im- 


S<l*n,*«»£< 


•fc  l         FATH  CF|  RAYS  BCF  C 

I  4 


&\        fATHCF, 

\\\  I 


Fig.  12.     Experiment  for  determining  the  velocity  of  a  corpuscle. 

pact  of  the  corpuscles,  the  electrometer  con  nor  tod  with  C  is 
quite  unaffected.  This  shows  us  that  the  corpuscles  tend  to 
travel  in  straight  lines.  The  next  thing  to  be  noticed  is  that 
on  the  approach  of  a  magnet  the  corpuscles  may  be  deflected 
so  that  they  fall  on  C,  and  its  electrometer  will  show  a  cor- 
responding deflection,  Fig.  13.  A  photographic  representa- 
tion of  a  beam  of  corpuscles  shows  plainly  the  deflection 


FACTORS   OF   A  CORPUSCLE. 


57 


they  undergo.     The  path  of  the  corpuscles  is  made  visible 
by  a  special  method  to  be  afterward  considered. 

This  fact,  namely,  that  a  magnetic  force  will  bend  a  beam  of 
corpuscles,  solves  our  problem.  It  may  be  shown  beyond  all 
question  that  when  a  magnet  is /presented  at  a  stream  of 
corpuscles,  each  corpuscle  tends  to  describe  a  circle  at  right 
angles  to  the  magnetic  force,  and,  furthermore,  that  the 


Fig.  13.     Showing  rays  deflected  by  horseshoe  magnet. 

radius  of  this  circle  equals  ^  where  m  is  the  mass  of  the 

corpuscle,  v  its  velocity,  e  its  electrical  charge,  and  H  the 
amount  of  the  magnetic  force.  Returning  to  the  diagram 
of  the  apparatus,  you  will  find  that  it  is  possible  to  meas- 
ure the  radius  of  this  circle  of  corpuscular  motion ;  for  when 
the  magnetic  force  is  just  sufficient  to  deflect  the  corpuscles 
wholly  to  the  electrode,  C,  they  travel  from  E  to  C  along 


58  THE  NEW  KNOWLEDGE. 

the  arc  of  this  very  circle.  The  size  of  the  circle  is  indicated 
in  the  diagram,  and  the  length  of  its  radius  is  fixed  by  the 
relative  positions  of  E  and  C. 

Now,  the  magnetic  force  that  is  just  sufficient  to  cause 
the  deflection  of  the  particles  to  C  is  easily  measured;  and 
hence,  we  have  the  following  equation: 


mv 


Radius  of  circle    (which  we   know)-e  x  H  (which  we  know)> 

which  with  a  shifting  of  one  quantity  to  the  other  side  of 
the  equation,  is:' 


Radius  of  circle  (known)  X  magnetic  force  (known) = 


And  we  are  thus,  to  some  extent,  forwarder,  at  least;  for  we 
have  a  definite  value  for, 

the  mass  of  the  corpuscle  X  its  velocity 
its  electrical  charge 

Is  there  any  hope  of  our  going  further?    There  is.     We 
must  now  determine  the  velocity  of  the  corpuscles. 


CHAPTER  V. 
THE  SPEED  OF  A  CORPUSCLE  AND  How  IT  is  ESTIMATED. 

In  order  to  determine  how  fast  corpuscles  move,  we 
should  consider  that  during  the  flight  of  a  corpuscle  from 
the  aluminum  plate,  A,  until  it  passes  through  the  window 
of  the  screen,  E,  energy  is  being  acquired  by  it  from  the 
electric  fiold  which  exists  between  the  two  plates,  A  and  E', 
both  charged  electrodes.  This  energy  may  be  represented 
by  Ve,  where  V  is  the  difference  in  electric  potential  between 
the  two  plates  and  e  the  electrical  charge  on  the  corpuscb. 
Xow,  the  kinetic  energy  of  a  body  may  be  represented 

also  by  the  familiar  formula,  ^y~.    Hence  we  have,  ^-==Ve, 

in  which  in  is  the  mass  of  the  corpuscle,  v  its  velocity,  e  its 
electrical  charge,  and  V  the  difference  of  electrical  poten- 
tial between  the  plate  and  the  screen.  Placing  V  over  to 

the  other  side  of  the  equation,  we  find  that  e  =^Y-     From 

our  equation  concerning  the   magnetic  deflection,  R=^p 

it   is    evident    that  e   must  also   equal  ^.     And  hence, 

2==  Simplify  this  equation  and  you  will  find  that 


=       .     That  is  to  say: 


TT  ,     ..       t  i       Twice  difference  of  potential 

\  elocity  of  corpuscle  = 


Radius  oi  circle  X  magnetic  force 

The  value  of  the  three  terms  on  the  right-hand  side  of 
the  equation  are  -known;  and  the  problem  is  solved. 
So  determined,  the  velocity  of  the  corpuscles  is  simply 

(59) 


60  THE   NEW  KNOWLEDGE. 

prodigious.  The  speed  of  the  swiftest  rifle  bullet  is  insig- 
nificant in  comparison.  Their  velocity  is  not  at  all  con- 
stant, for  it  depends  on  the  electric  force  with  which  they 
are  charged,  and  upon  the  amount  of  air  left  in  the  vessel; 
but  the  corpuscle  that  does  not  travel  with  a  speed  a  thou- 
sand times  that  of  the  swiftest  cannon  ball,  which  is  two 
thousand  miles  an  hour,  is  slow  indeed.  The  only  velocity 
with  which  the  speed  of  corpuscles  can  be  compared  is  that 
of  light — 186,000  miles  a  second — and  corpuscles  have  been 
observed  with  about  half  this  velocity.  In  fact,  the  velocity 
of  a  corpuscle,  depending  on  the  conditions,  may  be  taken 
as  anywhere  from  10,000  to  90,000  miles  a  second. 

We  see,  then,  that  a  candle  flame,  or  a  glowing  wire,  or  a 
metal  exposed  to  light,  is  not  by  any  means  the  restful 
object  it  appears.  Every  object  in  the  neighborhood  of 
such  bodies  must  be  continuously  bombarded  by  bullets 
flying  with  an  enormous  velocity;  and  small,  indeed,  must 
these  bullets  be  to  leave  us  all,  so  long,  utterly  unsuspicious 
of  their  existence.  But  small  as  they  are,  we  must  weigh 
them ;  and  to  do  this  we  must  first  of  all  derive  the  value 

"i- 


CHAPTER  VI. 

THE  RELATION  OF  THE  CHARGE  ix  A  CORPUSCLE  TO  ITS 
MASS:  How  IMPORTANT  IT  is. 

THE  value,  -,  is  a  most  important  one  in  the  elucida- 
tion of  the  nature  of  corpuscles.  By  it  is  meant  simply 
the  ratio  of  the  electrical  charge  on  the  corpuscle,  e,  to  its 
mass,  m;  and  it  is  evident  that,  having  obtained  this  value, 
we  need  only  determine  the  electrical  charge  to  know  the 
mass  of  the  corpuscle;  that  is  to  say,  the  amount  of  mat- 
ter of  which  it  is  composed. 

It  is  easy  to  obtain  the  value  of  -  from  our  equations, 

(1)  RH=—  ,  and  (2)  v=.     For,  substituting  v  in  the 


first  equation  for  the  value  of  v  in  the  second  equation,  we 

have, 

2V 

m  X  ]JH 
RH-     — 

Hence, 

e  2V 


m         (RH)2 

And  since  V,  R  and  H  are  known,  there  is  no  more  diffi- 
culty— the  problem  is  solved.  On  the  basis  of  the  experi- 
ment, £-10,000,000.  Hence,  m-  10>QOeQ>00().  So  that 

all  we  have  now  to  do  is  to  determine  the  charge  on  the  cor- 
puscle and  divide  it  by  10,000,000  to  obtain  the  mass  of 
the  corpuscle. 

(61) 


62  THE  NEW    KNOWLEDGE. 

Before  proceeding  to  this,  however,  there  are  certain  in- 
teresting facts  about  (-  =  10,000,000  that  deserve  our  at- 
tentive consideration.  The  first  fact  is,  that  no  matter 
from  what  source  these'  corpuscles  come,  whether  glowing 
metals,  gases  or  what  not — no  matter  by  what  method 
they  are  evolved,  whether  light,  electricity  or  heat — and 
no  matter  by  which  one  of  the  many  experimental  methods 

the   value   of         i.3  deduced — the  result,  within  the  limits 

of  experimental  error,  is  a  constant  quantity,  about 
10,000,000.  This  shows  us  that  the  corpuscles,  whatever 
their  nature,  are  independent  of  the  kind  of  matter  from 
which  they  are  evolved.  The  second  interesting  fact  is 

that  the  value  of  -  for  the  lightest  chemical  ion  known, 
that  of  hydrogen,  is  only  about  10,000,  which  is  one  thou- 
sand times  less  than  the  value  of  -  for  the  corpuscle.  * 

m 

The  question  now  arisas:  Is  this  thousand  times  differ- 
ence between  the  ion  and  the  corpuscle  due  to  a  difference 
in  the  masses  of  the  ions,  or  to  a  difference  in  the  electrical 
charge,  or  to  both  ?  Let  us  have  at  e,  then,  to  settle  the 
matter. 


CHAPTER  VII. 

How  THE  ELECTRICAL  CHARGE  ix  A  CORPUSCLE  is  ESTI- 
MATED: A  NEW  USE  FOR  CLOUDS. 

In  order  to  find  the  electrical  charge  on  the  corpuscle,  it 
is  best  to  consider,  now,  the  influence  of  ions  on  the  forma- 
tion of  clouds.  This  cloud  formation  is  a  very  striking  ef- 
fect produced  on  moist  air  by  the  presence  of  ions,  whether 
positive  or  negative,  whenever  the  air  is  expanded  a  quarter 
of  its  original  volume.  The  fact  seems  to  be  that  each 
corpuscle  acts  as  a  nucleus  about  which  the  moisture  of 
the  air  collects,  so  that  it  becomes  the  centre  cf  a  visible 
drop  t>f  water,  and,  where  before  there  existed  a  moist, 
invisible  gas,  there  now  suddenly  appears  a  beautiful  cloud. 

Though  corpuscles  due  to  any  of  the  ionizing  agencies 
mentioned  in  Chapter  I  cause  this  cloud-condensation,  one 
of  the  best  for  the  purpose  is  the  X-rays,  which  are  pecu- 
liarly efficient  in  forming  clouds  in  any  gas  through  which 
they  pass.  The  mechanism  of  the  experiment,  in  its  sim- 
plicity, is  a  mass  of  moist  gas  enclosed  in  a  glass  vessel, 
through  which  are  passing  weak  X-rays  and  in  which  the 
moist  air  may  suddenly  be  expanded  with  the  formation  of 
a  cloud  of  water  drops.  But  the  determination  of  the  many 
factors  which  it  is  necessary  to  know  in  order  to  arrive  at 
the  electrical  charge  on  a  corpuscle  by  this  means,  is  most 
formidable. 

The  procedure  is  somewhat  as  follows  :  The  velocity  with 
which  each  drop  of  water  falls  is  measured;  from  this,  the 
radius  of  the  drop  may  be  calculated;  knowing  the  radius 

(63) 


64  THE   NEW  KNOWLEDGE. 

of  the  drop,  it  is  next  possible  to  determine,  by  calculation 
and  experiment,  the  mass  of  water  deposited  from  the 
cloud ;  and  knowing  these  two  factors,  the  number  immedi- 
ately follows  from  the  equation,  n=-f7a3 ,  where  n  is  the 
number  of  drops  (and,  hence,  the  number  of  corpuscles), 
|  the  mass  of  water  deposited  in  the  form  of  drops,  and  a 

the  radius  of  the  drop.  Having  the  number  of  corpuscles 
in  the  gas,  the  electrical  charge  on  each  individual  corpuscle 
follows  by  experimentally  determining  the  total  electrifica- 
tion and  dividing  by  the  number. 

The  value  of  e  turns  out  to  be  0.00000000034  in  electro- 
static units.  And,  now,  finally,  we  are  in  a  position  to  know 
the  mass,  or  amount  of  matter,  in  a  corpuscle. 


CHAPTER  VIII. 

HOW  THE  MASS  OF  A   CORPUSCLE  IS  DETERMINED  I   DlSCOV- 
ERY  OF   THE  ONE  THING. 


It  will  be  remembered  that  ^=10,000,000.     Therefore, 
m==  IAAAAAAA-     Or,  since  e,  &$  we  have  determined,  has  the 

1(J,0(JU,0(JU 


value  of  0.00000000034,  m=      000.     And  this  is  the 

weight  of  a  corpuscle.  Well,  we  need  not  translate  this 
value  in  to  a  fraction  telling  us  just  what  portion  of  a  gram 
the  weight  of  a  corpuscle  is.  It  would  constitute  a  dec- 
imal stretching  from  one  side  of  the  page  to  the  other. 
What  we  want  particularly  to  know  is  the  relation  between 
the  weight  of  a  corpuscle  and  the  weight  of  an  atom. 

This  falls  neatly  into  our  hands;  for  it  turns  out  that 
the  electrical  charge  on  a  hydrogen  ion  is  exactly  the  same, 
within  the  limits  of  experimental  error,  as  the  electrical  charge 
on  a  corpuscle.  Now,  it  will  be  remembered  that  the  total 

value  of  ^  for  a  hydrogen  ion  is  1,000  times  less  than  the 
total  value  of  -  for  a  corpuscle.  If,  therefore,  the  mass 

of  a  corpuscle  equals  0.00000000034  divided  by  ten  million, 
and  the  mass  of  an  atom  equals  0.00000000034  divided  by 
ten  thousand,  it  follows  that  the  mass  of  the  hydrogen 
ion  is  one  thousand  times  greater  than  the  mass  of  a  cor- 
puscle ! 

So,  starting  with  a  candle  flame  and  a  gold-leaf  electro- 
scope, we  have  been  carried  irresistibly  to  the  conclusion 
5  (65) 


66  THE   NEW  KNOWLEDGE. 

that  there  are  bodies  f\  thousand  times  smaller  than  the  smallest 
atom.  Next  we  have  seen  that,  no  matter  what  their  source, 
tHese  little  particles  are  all  alike  in  nature  and  size.  And, 
finally,  we  know  that  they  constitute  an  actual  part  of  the 
forms  of  matter  from  which  they  fly.  The  far-reaching  influ- 
ence of  these  conclusions  on  the  inner  structure  of  the  uni- 
verse explains  the  painful  efforts  we  have  made  to  show 
how  they  are  obtained,  and  why — since  the  how  is  not  so 
important  in  this  world  as  the  why — we  are  so  sure  in  our 
conclusions. 

That  we  have  in  a  corpuscle  the  veritable  key  to  many 
a  mystery,  it  will  be  the  function  of  the  latter  part  of  our 
book  to  disclose.  Our  present  duty  is  to  elucidate  still 
farther  the  nature  of  these  strange  little  bodies.  And,  for 
this  purpose,  there  is  no  place  in  which  they  are  better 
developed,  or  in  which  they  have  greater  freedom  from  ex- 
traneous influences,  than  in  the  cathode  rays. 


CHAPTER  IX. 

PROPERTIES  OF  CORPUSCLES:  CATHODE  RAYS. 

In  the  absence  of  any  of  the  ionizing  agencies  we  have 
so  far  considered,  the  very  high  resistance  of  the  air  can 
be  overcome  only  by  the  application  of  intense  electrical 
forces.  Instead  of  an  invisible  leakage  we  then  obtain  a 
sudden  spark,  as  one  sees  any  day  in  the  discharge  of  an 
electrical  machine  or  in  a  lightning  flash.  But  this  spark 
discharge  is  due  to  the  fact  that  the  air  or  gas  is  at  the 
normal  pressure  of  the  atmosphere,  about  15  Ibs.  to  the 
square  inch.  Just  so  soon  as  we  begin  to  decrease  this 
pressure  the  phenomenon  begins  to  change;  and  this 
change  goes  on  progressively  until  its  character  becomes 
absorbingly  interesting. 

The  less  the  pressure  the  easier  it  is  to  form  these  little 
negatively  electrified  particles  under  the  influence  of  elec- 
tric forces.  If  an  electric  machine  or  induction  coil  be 
connected  with  metallic  terminals  fused  into  a  glass  bulb, 
so  arranged  in  connection  with  an  air  pump  that  the  air 
can  be  gradually  withdrawn,  one  of  the  most  beautiful 
experiments  in  physical  science  makes  evident  the  maxi- 
mum properties  of  corpuscles.  When  the  air  has  been 
withdrawn  until  it  has  a  pressure  of  about  one  ten-thou- 
sandth of  an  atmosphere,  the  first  effect  noticeable  in  the 

(67) 


68 


THE   XE\V    KNOWLEDGE. 


i.u, 


bulb  is  illustrated  in  Fig.  14.     Near  the  positive  pole,  a,  is 

.situated  a  cloud  of  light  which,  when  the  pressure  of  the 
air  and  the  current  of  electricity  lie  within  cer- 
tain definite  limits,  shows  beautiful  fluctuating 
striations. 

The  negative  pole,  or  cathode,  A',  is  sur- 
rounded by  a  faint  glow,  and  beyond  the  glow 
lies  a  dark  space,  k  to  b.  If  the  exhaustion  of 
the  bulb  be  now  increased,  the  dark  space 
extends  farther  and  farther  through  the  bulb, 
until,  finally,  it  strikes  the  other  side  of  the 
bulb  and  impinges  on  the  glass.  When  it  strikes 
the  glass  a  brilliant  phosphorescent  light  ap- 
pears, green  if  the  glass  contain  soda,  blue  if 
it  contain  lead,  and  the  glass  itself,  or  the  metal 
within  the  bulb,  becomes  a  source  of  X-rays. 
Fig.  16  is  a  photographic  representation  of  such 
a  bulb  in  action.  The  positive  and  negative 
terminals  (the  anode  and  cathode)  are  marked  -f- 
and  —  respectively.  Looking  only  at  the  wire 
^Y  which  the  current  leaves  the  bulb  (this  wire 

ena   in   vac-  is  called  the  cathode ;  it  is  the  one  marked  — 

uum  tube.       in  the  figure),  you  will  see  a  velvety  glow  about 

the    terminal   of  the   wire  within 

the  bulb.     In  front  of  this  is  the 

space   called   the  dark   space;  in 

front  of  this,   again,  the  bulb   is 

luminous  for  some  distance,   this 

luminous  portion  being  called  the 

negative   glow;    and,    finally,  tlie 

brilliant    phosphorescence   of   the 

pear-shaped  end  of  the  tube  will  showing  that  tin-  pimsphores- 

be  noticed  as  a  mass  of  white.         cen<>(' »™«  '"""  th"  cathode, 


.  14. 


PROPERTIES  OF  CORPUSCLES.  69 

It  was  soon  discovered  that  the  phosphorescence  in  the 
end  of  the  bulb  was  caused  by  something  coming  from  the 
neighborhood  of  the  cathode,  for  a  solid  placed  between 
the  cathode  and  the  end  of  the  bulb  casts  a  shadow  on  the 
bulb.  An  example  of  this  effect  is  shown  in  Fig.  15,  where 
the  shadow  is  caused  by  a  maltese  cross  of  mica,  placed 
between  the  cathode  and  the  end  of  the  bulb.  The  shape 
of  the  shadow  shows  that  the  cause  of  the  phosphorescence 
travels  in  straight  lines,  and  that,  moreover,  it  comes 
straight  from  the  cathode.  It  is  to  the  agent  producing 
this  phosphorescence  in  the  bulb  that  the  name,  cathode 
rays,  has  been  given. 


Fig.  16.     Photographic  representation  of  a  vacuum  tube  in  action. 

Xow,  cathode  rays  constitute  simply  a  beam  of  corpuscles; 
that  is,  they  consist  of  negatively  electrified  particles  hav- 
ing a  velocity  equal  to  that  of  corpuscles  obtained  in  other 
ways,  and  their  mass  is  a  thousand  times  less  than  the  mass 
of  a  hydrogen  atom. 

PHOSPHORESCENCE . 

A  very  large  number  of  bodies  give  out  a  phosphorescent 


70  THE   NEW   KNOWLEDGE. 

light  when  exposed  to  a  bombardment  of  the  corpuscles  in 
cathode  rays.  This  phosphorescence  is  very  beautiful,  its 
color  depending  on  the  nature  of  the  substance  struck.  The 
spectrum  given  out  by  these  bodies  is  generally  a  continuous 
one,  but  certain  rare  earths,  such  as  yttrium,  yield,  on  cor- 
puscular bombardment,  a  bright-line  spectrum  ;  and  this 
fact  has  been  of  great  importance  in  the  study  of  the  rare 
earths. 

The  power  of  glass  to  phosphoresce  under  these  rays  has 
already  been  referred  to.  It  ought  to  be  stated,  however, 
that  the  glass  will  in  time  "grow  tired."  This  may  be 
seen  with  the  apparatus  shown  in  Fig.  15,  where,  if  the 
cross,  which  is  on  hinges,  be  thrown  clown,  the  phosphores- 
cence of  that  part  of  the  glass  which  has  hitherto  been  in 
the  shadow  of  the  cross,  is  now  much  brighter  than  that  of 
the  surrounding  glass. 

The  substances  barium  platino-cyanide  and  calcium  tung- 
state  are  exceedingly  sensitive  to  the  impact  of  corpuscles. 
Their  phosphorescence  is,  in  fact,  used  to  detect  the  pres- 
ence of  corpuscles. 

CHEMICAL    EFFECT. 

Corpuscles  cause  chemical  changes  in  certain  bodies  on 
which  they  fall.  Thus,  rock  salt  takes  a  beautiful  violet 
color,  which,  unless  exposed  to  moisture,  it  will  retain  for 
years.  Lithium  chloride  is  remarkably  sensitive  to  the  im- 
pact of  corpuscles.  If  a  beam  of  corpuscles  be  slowly  moved 
over  the  salt  by  a  magnet,  the  path  of  the  beam  traces  out 
a  colored  band  on  the  surface  of  the  salt. 

I  IK  ATI  XG    EFFECT. 

Corpuscles  heat  a  body  on  which  they  fall.  Thoy  nmy 
be  concentrated  by  a  bowl-slmpcd  cathode,  such  as  shown 


PROPERTIES  OF  CORPUSCLES. 


71 


in  Fig.  17;  and  a  piece  of  platinum,  if  placed  in  the  focus, 
may  be  raised  to  a  white  heat;  and  glass  may  be  melted, 
and  a  diamond  charred. 


Fig.  17.     Cathode  rays  of  corpuscles  brought  to  a  focus. 
MECHANICAL    EFFECT. 

Corpuscles,  when  they  strike  against  an  object,  tend  to 
push  it  away.  This  is  very  prettily  shown  in  the  appara- 
tus in  Fig.  18,  where  the  impact  of  the  corpuscles  in  the 
cathode  rays  makes  the  little  carriage  move  from  one  end 
of  the  rails  to  the  other. 


Fig.  18.     Showing  that  corpuscles  will  move  a  body  which  they  strike 


72  THE   NEW   KNOWLEDGE. 

POWER  TO  PENETRATE  MATTER. 

It  was  at  first  supposed  that  solid  bodies  were  absolutely 
impenetrable  to  these  corpuscles.  Nowadays,  however,  we 
know  that  this  is  not  so.  Lenard  has  made  a  tube  which 
has  in  it  a  small  window  of  aluminum  foil,  and  on  shoot- 
ing the  corpuscles  against  this  window,  he  found  that  they 
passed  straight  through  it,  and  so  got  outside  the  tube, 
where  they  could  be  more  easily  investigated.  Cathode 
rays  which  have  passed  through  the  glass  bulb  into  the 
outer  air  are  consequently  called  Lenard  rays. 

LENARD   RAYS. 

It  will  be  understood  that  these  rays  consist  simply  of 
corpuscles  which  have  passed  through  an  aluminum  window, 
and  are  in  no  way  different  from  corpuscles  in  general  or 
from  the  cathode  rays  within  the  tube.  They  have  turned 
out  to  be  very  useful,  however,  in  determining  the  Law  of 
Absorption.  The  absorption  of  ordinary  light  by  different 
substances  bears  no  relation  to  the  density,  or  weight,  of 
the  absorbing  medium.  Heavy  materials,  like  iron  or  glass, 
light  bodies,  such  as  cork  or"  water,  may  be  transparent  or 
opaque  to  ordinary  light,  as  the  case  may  be.  On  the 
other  hand,  in  the  absorption  of  corpuscles  in  the  Lenard 
rays  very  different  phenomena  appear. 

A  given  thickness  of  material,  whether  gas,  liquid  or  solid, 
absorbs  these  rays  simply  in  proportion  to  their  density, 
and  entirely  indeixmdently  of  any  other  property.  Thus, 
though  the  density  of  the  lightest  substance  is  only  one 
sixty-millionth  of  the  heaviest,  throughout  this  enormous 
range  nil  substances,  including  air,  carbonic  acid  gas,  paper, 
copper,  glass  and  gold,  absorb  these  rays  in  direct  propor- 
tion to  the  relative  weight  of  the  substances  involved. 


PROPERTIES  OF  CORPUSCLES.  73 

CORPUSCLES  AND  X-RAYS. 

When  the  air  pressure  in  the  bulb  producing  cathode 
rays  is  so  low  that  the  glass  of  the  bulb  becomes  brilliantly 
phosphorescent,  an  entirely  different  sat  of  rays  proceeds 
from  the  tube,  having  properties  that  differentiate  them 
altogether  from  the  cathode  rays,  or  corpuscles,  that  pro- 
duce them  by  their  impact  on  the  glass  or  on  a  metal 
plate  within  the  bulb.  These  rays  illuminate  a  phospho- 
rescent screen,  affect  a  photographic  plate,  and  have  an 
astonishing  power  of  penetrating  substances  opaque  to  or- 
dinary light.  They  are  called  X-rays  because  at  the  time 
of  their  discovery  their  nature  was  an  unknown  quantity. 
And  so  it  is,  to  a  certain  extent,  even  now.  They  are  not 
corpuscles;  though  it  is  not  one  of  the  least  interesting 
properties  of  corpuscles  that  they  produce  X-rays.  Their 
probable  nature,  and  their  relation  to  corpuscles,  will  be 
considered  when  we  wish  to  make  use  of  them  in  the 
elucidation  of  another  problem. 

CORPUSCULAR    CONDENSATIONS. 

Except  in  the  phenomena  of  radio-activity,  which  con- 
stitutes the  subject-matter  of  the.  next  part  of  our  work, 
these  ultra-atomic  particles,  or  corpuscles,  are  found  only 
in  gases  or  metals  at  high  temperatures  or  in  the  low  pres- 
sure which  exists  in  a  good  vacuum.  The  reason  for  this  is 
that  no  sooner  is  a  corpuscle  let  loose  than  it  tends  to  unite 
itself  with  anything  else  available,  whether  this  be  another 
corpuscle,  an  atom  or  a  molecule;  so  that  it  is  only  in  the 
long,  open  spaces  of  a  good  vacuum,  where  they  have  a 
path  free  from  much  chance  of  collision,  that  we  can  study 
them  as  they  are.  At  the  ordinary  pressure  of  the  atmos- 
phere, or  at  ordinary  temperatures,  they  are  no  sooner  set 


74  THE   NEW  KNOWLEDGE. 

free  than  they  become  nuclei,  about  which  atoms  and  mole- 
cules collect,  until  they  form  masses  many  times  larger 
than  the  original  molecules  of  the  gas.  This  is  quite  con- 
sistent with  what  we  have  learned  concerning  the  formation 
of  clouds  in  the  presence  of  corpuscles. 

Resume  of  what  we  have  learned  about  corpuscles. 

Corpuscles  are  generated  from: 

(1)  Burning  gases. 

(2)  Glowing  metals  and  carbon. 

(3)  Electrical  discharges  in  gases  at  low  pressures. 

(4)  X-rays. 

(5)  Metals  on  the  impact  of  ultra-violet  light. 

Nature  and  properties: 

(1)  They  are  negatively  electrified  particles. 

(2)  They   have    a   velocity   of   from    10,000    to 

90,000  miles  a  second. 

(3)  They  have  the   same  electrical   charge  as  a 

hydrogen  ion.  cJt**Jr 

(4)  They  have  a  mass  equal  to  ^one  ^»c<-  thous- 

andth of  a  hydrogen  atom. 

(5)  They  discharge  electrified  bodies. 

(G)    They  are  deflected  by  a  magnet  so  that  they 
tend  to  go  in  a  circle. 

(7)  They  are  deflected  by  an  electrostatic  force. 

(8)  They  cause  phosphorescence  in  bodies  which 

they  strike. 

(9)  They  give  rise  to  heat  in  bodies  which   they 

strike. 

(10)  They    communicate    mechanical    motion    to 

bodies  which  they  strike. 


PROPERTIES  OF  CORPUSCLES.  75 

(11)  They  give  rise  to  X-rays  in  bodies  which  they 

strike. 

(12)  They  are  absorbed  by  all  bodies  in  direct 

proportion  to  the  density  of  those  bodies. 
(12)  They  act  as  nuclei  about  which  atoms  and 
molecules  collect. 


CHAPTER    X. 
POSITIVE  IONS:  THE  OTHER  KIND  OF  PARTICLES. 

Has  the  reader  forgotten  that  the  gaseous  ions  of  the 
candle  flame  and  the  glowing  wire  consist  of  particles  of 
two  kinds,  the  one  carrying  negative  electricity,  the  other 
positive  ?  Since  the  negative  particles,  or  corpuscles,  have 
turned  out  to  possess  properties  so  unprecedented  and  un- 
locked for,  it  is  high  time  to  renew  our  inquiries  concern- 
ing the  positive  particles. 

These  positive  particles  afford  a  surprise.  Though  they 
may  be  developed  by  any  of  the  forgoing  methods,  in  their 
properties  they  are  almost  diametrically  opposed  to  cor- 
puscles. 

(1)  They  carry  positive  electricity,  not  negative. 

(2)  Their  velocities  are  less  than  those  of  corpuscles. 

(3)  Their  electrical  charge  is  of  the   same  order  as  that 

of  an  ordinary  atom. 

(4)  The  value  of  ^  is   one    thirty-thousandth  of  ^  for 

a  corpuscle. 
(o)  Their  mass   is  a  thousand    times    as    great  as   the 

mass  of  a  corpuscle,  and  is  about  equal  to  that  of 

an  atom  of  ordinary  matter. 
(6)  They  can  be  deflected  by  a  magnet  only  to  a  slight 

extent,  and    require  for  this  deflection  a  magnetic 

field   immensely  strong. 

It  is  evident,  then,  from  a  comparison  of  the  two  kinds 
(76) 


POSITIVE   IONS.'  t  / 

of  particles,  that  "  Codlin  is  our  friend,  not  Short  " — the 
corpuscle,  not  the  positive  ion.  For,  though  we  shall  refer 
to  the  positive  ion  again  and  again,  if  we  wish  to  know 
something  of  the  birth  of  matter,  the  decay  of  matter,  the 
nature  of  matter,  of  the  nature  of  electricity  and  the  rela- 
tion of  electricity  to  matter,  of  the  nature  of  the  sun  and 
the  sun's  rays,  of  the  possible  cause  of  gravitation,  the 
cause  of  clouds  and  rain,  and  the  reasonable  solution  of 
many  another  mystery — if  we  wish  to  know  something  of 
all  this,  the  corpuscle  is  our  most  informing  friend. 

In  earnest  of  this,  we  may  say  that  so  far  as  we  have 
gone  in  this  part  of  our  work  there  is  barely  a  paragraph 
that  will  not  be  utilized  in  the  study  of  the  foregoing  prob- 
lems. Surely,  then,  we  have  in  the  corpuscle  the  fulcrum 
for  the  lever  of  thought,  the  philosopher's  desire,  the  one 
thing  to  explain  our  explanations,  for  which  alchemy  so 
earnestly  sought  in  the  dim,  vague  light  of  the  middle 
ages  and  called  it  the  philosopher's  stone,  and  for  which, 
chemistry,  the  daughter  of  alchemy,  has  so  sorely  felt  the 
need  to  make  herself  consistent  in  the  periodic  law. 

It  is  an  interesting  thought  that,  throughout  the  ages, 
in  this  search  for  the  one  thing,  the  medieval  scholar,  la- 
boriously poring  over  his  great  book  in  the  light  of  his  little 
candle,  and  the  modern  savant  in  his  laboratory,  radiant 
with  electric  illumination,  have  alike  been  literally  bathed 
in  the  light  of  the  truth— bombarded,  hands  and  face  and 
eyes,  by  the  one  thing,  with  only  that  short  space  lacking, 
between  the  retina  and  the  innermost  centre  of  the  brain 
where  the  power  of  deduction  lies,  to  know. 

Verily, 

"  Truth  is  within  ourselves;  it  takes  no  rise 
From  outward  things,  whate'er  you  may  believe. 


78  THE   NEW   KNOWLEDGE. 

and  to  KNOW, 

Rather  consists  in  opening  out  a  way 
Whence  the  imprisoned  splendour  may  escape, 
Than  effecting  entry  for  a  light 
Supposed  to  be  without." 


PART  IV. 


NATURAL  RADIO-ACTIVITY:    A  NEW 
PROPERTY  OF  MATTER. 


PART  IV. 

NATURAL  RADIO-ACTIVITY:     A  NEW  PROPERTY 
OF  MATTER. 


CHAPTER  I. 

ANTECEDENT  DISCOVERY. 

The  theme  of  this  present  part  of  our  book  is  of  a  new 
thing  done — the  discovery  of  a  new  natural  property  of 
matter,  and  an  explanation  of  this  property  in  terms  of 
what  we  already  know. 

If  one  questioned  the  discoverer — the  beginner  of  the 
work —  about  himself,  he  would  probably  say  that  his  work, 
possibly,  was  something — he  himself  was  nothing;  and  in  a 
measure  he  is  right ;  for  in  a  few  years  he  will  pass,  while  his 
work  will  endure  forever.  Still,  we  wish  to  know  him  for 
his  work's  sake,  and  surely  it  will  not  be  amiss  to  say  some- 
thing at  least  about  him. 

Henri  Becquerel,  Membre  de  Flnstitut,  is  the  discoverer 
of  Becquerel  rays,  the  basis  of  the  phenomena  of  radio- 
activity. He  comes  very  honestly  by  his  powers.  His 
grandfather,  Antoine  Cesar  (1788-1878),  through  sixty  years 
of  indefatigable  labor,  contributed  more  than  five  hundred 
memoirs,  works  of  note  on  mineralogy  and  electricity.  His 
father,  Alexandre  Edmond  (1820-1891),  was  the  author  of  so 
'  6  (81) 


82  THE    NEW  KNOWLEDGE. 

many  memoirs  that  they  constitute  practically  a  history  of 
the  relations  of  optics  to  electricity  through  the  past  fifty 
years.  Henri  Becquerel,  the  son,  was  subjected  to  the  train- 
ing and  influence  of  these  honoured  men,  and  it  is  little  won- 
der, then,  that,  through  heredity  and  environment,  he  should 
bear  the  face  of  one  who  sends  his  soul  into  the  invisible — 
for  that,  in  good  solid  truth,  is  what  every  true  experi- 
menter literally  does. 

In  due  time  he  succeeded  to  the  Professorship  of  Physics, 
the  chair  of  his  father,  and  began  his  work  in  their  laboratory 
in  the  quaint  old  home  of  Cuvier  in  the  Jardin  des  Plantes, 
— "a  laboratory  to  which  I  had  gone,"  he  says,  "from  the 
time  I  was  able  to  walk."  There  he  wrought  nobly  for  the 
credit  of  his  name,  until  Rontgen's  discovery  of  the  X-rays 
initiated  an  investigation  which  culminated  in  the  discovery 
of  the  Becquerel  rays  and  radio-activity. 

Now,  Becquerel  did  not  discover  his  rays  and  their  radio- 
activity out  of  nothing.  Every  scientific  discovery  has  a 
genealogy  of  its  own,  going  back  to  the  primal  ancestor  of 
all  thoughts;  no  discovery  comes  into  the  world  parentless 
of  previous  conceptions.  Here  is  a  table  showing  a  few 
steps  in  the  genealogy  of  the  Becquerel  rays : 

GENEALOGY  OF  THE   RAYS. 

Cathode  Kays. 

Lenard  Rays _X-Rays 

S-Rayg                         _Niewenglowski's  Rays. 
N-Rays ! Beequerrl  Hays. 

X-rays  are  in  some  way  entangled  with  the  phosphores- 
cence in  a  Crookes'  tube.  Consequently,  the  discovery  of 


ANTECEDENT  DISCOVERY.  83 

Professor  Rontgen  set  men  wondering  as  to  whether  the 
power  of  emitting  penetrating  rays  might  not  be  a  property 
of  phosphorescent  bodies  in  general.  In  this  instance  there 
was  Niewenglowski,  who  made  the  interesting  discovery  that 
some  such  rays  were  actually  emitted;  that  much  at  least. 
His  experiment,  as  afterward  repeated  by  Becquerel,  is  per- 
fectly demonstrative.  A  certain  compound  of  sulphur  and 
calcium,  cajdmn_sjri]}hide,  which  is  the  basis  of  luminous 
paint,  shines  in  the  dark  after  exposure  to  sunlight — that  is, 
it  is  phosphorescent.  Niewenglowski  placed  a  photographic 
plate  in  a  plate-holder,  and  instead  of  a  cover-slide,  he  in- 
serted a  thin  sheet  of  aluminum.  The  plate  was  thus  com- 
pletely sheltered  from  the  action  of  light.  Upon  the  sheet  of 
aluminum  he  placed  squares  of  thin  glass,  and  upon  these, 
in  turn,  pieces  of  a  certain  calcium  sulphide  previously  ex- 
posed to  light,  which  were  protected  from  external  influences 
by  dome-shaped  clock-glasses.  The  arrangement  of  the  ex- 
periment is  seen  in  Figure  19,  the  cover-slide  of  aluminum,  the 


Fig.  19.  Xiewenglowski's  Experiment. 

glass,  the  sulphide  above  it,  and  the  clock-glasses  covering 
all.  The  apparatus  was  left  in  the  dark  for  twenty-three 
hours.  The  plate  was  then  developed.  A  print  from  the 


84  THE  NEW  KNOWLEDGE. 

actual  plate,  which  is  here  produced  (Fig.  20)  leaves  no  muddy 
obscurity  for  the  reader.     Upon  the  plate  are  imprinted  the 


Fig.  20.    The  result  of  Niewenglowski  's  Experiment. 

square  of  glass  and  the  round  section  of  the  clock-glass  cover. 
The  rays  had,  necessarily,  to  pass  straight  through  the  alumi- 
num cover-slide  to  print  them  there.  It  was  thus,  then, 
that  the  question  was  asked  of  Nature,  "Does  this  sub- 
stance, this  calcium  sulphide,  emit  rays  which  will  pene- 
trate glass  and  metal  and  affect  a  photographic  plate?" 
And  Nature  answered  in  her  legible  signature,  "This  sub- 
stance will."  Are  these  rays  light?  The  answer  is  upon  the 
same  plate.  It  is  affirmative.  If  you  examine  the  im- 
print of  the  square  of  glass  upon  this  plate,  you  will  notice 
that  it  is  bordered  by  a  perfectly  white  line  which  has  been 
left  untouched  by  the  rays.  This  can  only  be  accounted  for 
by  supposing  that  they  were  bent,  or  refracted,  on  passing 
through  the  edges  of  the  glass  into  the  air.  Now  rays  that 
are  made  up  of  particles,  or  corpuscles  such  as  we  have 
studied  in  Part  III,  cannot  be  refracted  in  the  slightest  de- 
gree. Light  rays  always  are,  and  must  be,  from  their  very 
nature,  as  wave  motions.  Niewenglowski,  therefore,  dis- 
covered penetrating  rays  of  light  capable  of  passing  through 
a  sheet  of  metal,  a  substance  which  anybody  would  consider 


ANTECEDENT  DISCOVERY.  85 

opaque — not  X-rays,  nor  corpuscles,  but  light  rays  of  a  most 
remarkable  kind.  It  should  be  remembered,  however,  that 
these  penetrating  light  rays  were  not  given  off  by  the  sul- 
phide in  its  natural  condition.  It  had  previously  to  be  ex- 
posed to  sunlight,  whence  it  derived  its  energy. 


CHAPTER  II. 
THE  DISCOVERY  OF  RADIO-ACTIVITY. 

But  Becquerel,  abreast  of  the  same  wave  of  investiga- 
tion, thought  as  Niewenglowski.  He  says,  "For  my  part, 
from  the  day  on  which  I  first  had  knowledge  of  the  discovery 
of  Professor  Rontgen,  there  came  to  me,  too,  the  idea  of 
seeing  whether  the  property  of  emitting  very  penetrating 
rays  was  not  intimately  bound  up  with  phosphorescence." 
His  thought  was  soon  represented  concretely;  for,  taking 
fragments  of  various  phosphorescent  substances,  he  placed 
them  one  after  another  on  a  photographic  plate  enveloped 
in  black  paper,  and  thus  gave  them  an  opportunity  of  telling 
their  secrets  by  penetrating  the  paper  and  affecting  the  plate 
beneath.  In  this,  his  work  resembled  that  of  Niewenglowski  ; 
but  the  importance  of  it  is  and  the  luck  of  it  was,  that  he 
experimented  with  different  substances.  Out  of  all  the  dif- 
ferent substances  tried,  there  was  one,  uranium,  that  had 
waited  long  for  this  one  precious  day.  For  one  day  of 
twenty-four  hours  this  substance  lay  upon  a  photographic 
plate  enveloped  in  black  paper,  and  thus,  after  ages  upon 
ages  of  waiting,  found  utterance.  This  plate  was  affected. 
A  glance  at  Fig.  21  will  make  it  evident;  and  a  close  exami- 
nation will  reveal  the  shadow  of  the  copper  cross  through 
which  the  rays  had  to  pass.  The  plate  is  obscure,  as  would 
be  the  picture  of  the  approach  of  dawn;  and  it  is  equally 
significant.  It  reveals  nothing  but  the  presence  of  pene- 
trating rays.  "Here  I  am,"  said  Nature,  "now,  tell  me,  am 
I  Niewenglowski's  rays?"  "I  thought,  then,"  says  Bec- 
(86) 


THE    DISCOVERY   OF   RADIO-ACTIVITY.  87 

querel,  "that  it  was  necessary  previously  to  expose  the  sub- 
stance to  light  in  order  to  provoke  this  very  penetrating 
emission,  but  a  short  time  after  /  recognised  that  the  emission 
of  the  rays  was  produced  spontaneously,  even  when  the  sub- 
stance had  been  kept  completely  sheltered  from  any  previous 
exposure  to  light."  This  settles  the  question.  Niewenglow- 
ski's  rays  were  directly  due  to  the  action  of  the  sun  upon  the 
substance  which  emitted  them;  Becquerel  rays  arise  from  a 


Fig.  21.     Becquerel's  first  experiment. 

substance  whose  natural  property  it  is,  not  only  to  emit 
them,  but,  apparently,  to  manufacture  them.  It  may  be 
stated  here  that  since  this  discovery,  the  rays  emitted  by 
this  particular  fragment  of  uranium  compound  have  shown 
no  signs  whatever  of  diminution.  They  are,  apparently,  a 
permanent  property  of  this  form  of  matter.  Furthermore, 
it  was  soon  seen  to  be  a  matter  of  indifference  what  uranium 


88  THE   NEW  KNOWLEDGE. 

substance  was  employed.  Any  substance  containing  ura- 
nium gave  olf  the  rays.  Metallic  uranium  itself,  obtained 
in  Moissan's  electric  furnace,  gave  out  more  rays  than  any 
of  its  compounds.  More  than  that,  the  emission  of  the 
rays  turned  out  to  be  altogether  independent  even  of  phos- 
phorescence. Uranium  bodies,  whether  phosphorescent  or 
not,  emitted  rays.  Here,  then,  was  no  stored  up,  trans- 
formed sunlight,  such  as  Niewenglowski's  rays,  but  pene- 


Fig.  22.     Uraniuum  radiograph. 

trating,  continuous  emissions  from  a  substance  having  no 
relation  to  light.  The  emission  of  rays  capable  of  passing 
straight  through  copper  from  a  chemical  substance  in  its 
normal  condition  constituted  to  us  a  new  property  of  matter 
—a  new  thing  in  nature. 

So,  as  Becquerel  stood  in  his  laboratory  that  night,  with 
this  thought  in  his  mind  and  the  plate  in  his  hand,  he  ap- 
I  team  sharply  silhouetted  against  the  background  of  the  ages; 
he  is  comparable  with  that  Theophrastus  who,  two  thousand 


THE    DISCOVERY   OF   RADIO-ACTIVITY.  89 

years  ago,  rubbed  a  piece  of  amber  on  his  coat-sleeve  and 
noticed  that  it  attracted  bits  of  paper,  unknowing  that  this 
bit  of  amber  was  equal  to  the  lamp  of  Aladdin,  or  to  that 
Paleolithic  savage,  who,  the  first  of  all  men,  noticed  the  at- 
tractive powers  of  lodestone.  New  properties  of  matter  are 
not  so  common  that  their  significance  can  be  exaggerated. 
This  new  property  of  matter  was  called  radio-activity,  and  as 
such  it  takes  its  place  beside  magnetism,  electricity,  light  and 
heat. 


CHAPTER  III. 
DISCOVERY  OF  RADIO-ACTIVE  ELEMENTS. 

Radio-activity,  a  new  property  of  matter,  had  been  dis- 
covered, but  whence  its  source?  "The  metal  uranium  it- 
self," you  say,  "since  it  gives  off  the  rays."  Yes;  but  still  a 
doubt — a  little,  tiny  doubt — remained.  Was  it  not  possible 
that  the  power  of  emitting  rays,  the  radio-activity,  was  due 
to  some  small  impurity  present  in  the  uranium?  That  doubt 
was  the  key  which  unlocked  the  door  to  a  roomful  of  other 
discoveries. 

It  arose  in  the  minds  of  two  investigators  who  had  been 
interested  observers  of  Becquerel's  work,  M.  Pierre  Curie, 
Professor  of  Physics  in  the  School  of  Physics  and  Industrial 
Chemistry  at  Paris,  and  Madame  Skloclowski  Curie,  his  wife. 
They  resolved  to  investigate  the  ray-emitting  power  of  pitch- 
blende, the  parent  substance  from  which  all  uranium  is  ex- 
tracted. To  their  gratification  they  discovered  that  selected 
specimens  of  pitchblende  possessed  a  radio-activity  four 
times  greater  than  metallic  uranium  itself  (Figs.  23  and  34). 
Nature  never  insults  us  by  caprice,  and,  consequently,  we  find 
the  Curies  saying:  "It  becomes  then  very  probable  that  if 
pitchblende  has  so  strong  an  activity  it  is  because  the  min- 
eral contains,  in  small  quantities,  a  substance  wonderfully 
radio-active,  different  from  uranium  or  any  of  the  simple 
bodies  actually  known. 

"  We  proposed  to  ourselves  to  extract  this  substance  from 
pitchblende  and  we  have,  in  fact,  been  able  to  prove  that  it 
(90) 


DISCOVERY   OF   RADIO-ACTIVE   ELEMENTS. 


91 


Fig.  23.     Photograph  by  ordinary  daylight  of  a  section  of  pitchblende,  by 
Sir  William  Crookes. 


Fig.  24.  Photographic  imprint  of  the  same  section  of  pitchblende  as 
it  imprinted  itself  in  the  dark  when  laid  on  a  plate  enveloped  in  black 
paper.  The  white  portions  of  the  print  are  due  to  the  rays. 


92  THE    NEW    KNOWLEDGE. 

is  possible,  by  the  methods  of  ordinary  chemical  analysis,  to 
extract  from  pitchblende  substances,  of  which  the  radio- 
activity is  in  the  neighborhood  of  100,000  times  (jr eater  than 
tJiat  of  metallic  uranium." 

In  this  simple  manner  did  the  Curies  announce  their  dis- 
covery of  three  new  elements  with  transcendent  ray-emitting 
powers — radium,  polonium,  and  actinium  which  they  dis- 
covered with  Debierne.  Since  that  time  others  have  been 
discovered.  Of  these  strangers  in  the  world  of  matter,  we 
shall  select  radium  as  our  first  object  of  study,  as  it  is  the 
most  easily  obtained.  Its  discovery,  with  its  ray-emitting 
power  100,000  times  greater  than  uranium,  placed  in  the 
hands  of  investigators  a  mighty  engine  of  research  for  deter- 
mining the  properties  of  Becquerel  rays. 


CHAPTER  IV. 
RADIUM. 

Radium  has  never  been  isolated.  As  a  free  element  it  has 
never  been  seen,  never  been  touched,  never  been  handled,  as 
gold  and  iron  may  be,  but  it  is  manifest  in  the  properties  of 
its  compounds.  It  has  been  studied  only  in  combination 
with  other  elements,  chiefly  in  the  form  of  the  chloride  or 
bromide.  We  know  that  it  exists  as  an  element  different 
from  any  other  body  in  nature,  solely  and  completely  through 
the  fact  that  every  element  has  had  its  own  sign  manual,  or 
spectrum,  by  means  of  which  it  signifies  its  existence, 
whether  it  is  found  in  the  sun,  the  stars  or  the  laboratory. 
Fig.  25  is  the  spectrum  of  radium  as  obtained  byM.Demarcay 
from  a  small  quantity  of  chemically  pure  radium  chloride 
provided  by  Professor  Curie.  The  lines  numbered  at  the  top 


Fi.«r.  25.     Comparative  spectra  of  radium  and  calcium. 

of  the  picture  are  caused  by  no  known  element  on  the  earth 
or  in  the  heavens.     Therefore  radium  is  a  new  element. 

(93) 


94  THE   NEW  KNOWLEDGE. 

But  if  radium  is  an  element,  it  should  find  a  place  in  the 
family  grouping  of  the  periodic  law.     And  so  it  does.     An 
examination  of  the  chemical  behaviour  of  radium  shows  that 
it  is  allied  in  all  its  properties  to  barium.     It  is,  in  fact,  so 
.'  like  barium  that  it  is  almost  impossible  to  separate  one  from 
•  the  other.     The  family  resemblance  is  unmistakable.     Ba- 
rium is  a  sister  to  radium.     Now,  if  you  will  examine  the 
table  of  the  periodic  law,  page  28,  Part  II,  you  will  notice 
that  Barium  (Ba=137)  occurs  in  Group  II  and  that  there  are 
several  vacant  spaces  in  the  groups  marked  with  black  lines 
for  elements  hitherto  undiscovered.     Into  one  of  these  blank 
Group  II  spaces  radium  ought  to  fit  if  the  periodic  law  is 
~  the  expression  of  a  fact.     The  determining  factor 
Mo.       is,  of  course,  the  weight  of  the  atom.     That  set- 


Be  9  ties  its  place  in  the  table.  Now,  the  atomic 

M  24  weight  of  radium  has  been  determined  with  ex- 

treme accuracy  by  Madame  Curie,  and  her  re- 

Ca  40          suits  lead  to  the  value  225.     This  is  the  atomic 

^n  *L5          weight  of  an  element  which  should  fill  the  blank 

Cd  112        space  kelow  mercury  (Hg  200)  in  Group  II;  and 

Ba  137       so  ^  '1S  no  wonder  that,  chemically,  radium  should 

-  resemble  barium  for  they  belong  to  the  same  fani  ////. 

The  amount  of  radium    in  pitchblende  is  less 

than  one  ten-millionth  per  cent.,  rarer  than  gold 


in  sea  water;  and  the  quantities  of  the  much  rarer  polonium 
and  actinium  are  equally  infinitesimal.  The  difficulties  of  ex- 
traction are  immense.  The  residue  of  the  mineral  pitch- 
blende, out  of  which  the  radium  has  been  extracted  at 
Jochimsthal,  Bohemia,  is  sent  to  Professor  Curie's  works  at 
Ivry,  France,  where  it  is  precipitated  and  reprecipitated 
and  crystallized  and  recrystallixcd  an  a  max  ing  number 
of  times  in  order  to  separate  it  from  the  multitude  of  other 
things  contained  in  the  pitchblende.  Finally,  a  few  grains 


RADIUM.  95 

of  the  ton  or  so  of  material  reaches  Professor  Curie  him- 
self as  very  impure  radium  chloride  or  bromide.  It 
still  contains  many  times  its  weight  of  its  sister  barium 
and  now  under  Professor  Curie's  own  hands  it  under- 
goes the  final  laborious  process  of  fractional  crystallization 
by  means  of  which  the  barium  is  slowly  fined  away.  A 
slight  difference  in  solubility  is  practically  the  only  means  by 
which  the  separation  may  be  accomplished,  and  its  progress 
is  tested  by  the  increased  ray-emitting  power  of  the  sub- 
stance which,  beginning  with  2,000,  rises  to  10,000,  100,000 
and,  finally,  as  pure  "  radium,"  to  1,300,000  times  the  ac- 
tivity of  the  uranium  in  which  Becquerel  first  proved  the 
existence  of  the  new  property — radio-activity.  But,  alas! 
out  of  the  ton  of  material  but  barely  the  hundredth  of  a 
gram  remains.  It  is  like  attempting  to  collect  the  pollen 
of  a  single  flower  scattered  over  an  acre  of  ground. 

Considering  only  the  cost  of  the  pitchblende  from  which 
it  is  extracted,  the  value  of  radium  would  be  at  least  $10,000 
a  gram.  As  a  matter  of  fact,  not  much  more  than  a  gram 
exists.  Of  course  the  amount  is  slowly  increasing  and  it  is 
now  possible  to  buy  a  few  milligrams  of  varying  degrees  of 
purity  in  the  chemical  markets  of  the  world. 


CHAPTER  V. 


THE   BECQUEREL   RAYS   FROM   RADIUM. 

This  small  amount  of  radium  distributed  among  the 
scientific  workers  in  the  field  has  been  sufficient  for  the 
elucidation  of  the  properties  of  the  Becquerel  rays. 

LAW   OF   ABSORPTION. 

Their  surpassing  power  of  penetrating  matter  generally 
considered  opaque  led  to  their  discovery,  as  we  have  seen, 
and  it  was  therefore  one  of  the  first  properties  to  be  investi- 
gated. It  soon  became  evident  that  the  power  was  quite 
independent  of  the  kind  of  matter  through  which  they  passed. 

It  was  influenced  only 
by  the  density  of  the 
substance  interposed. 
Aluminum,  for  example, 
being  light  in  weight, 
is  to  the  Becquerel  rays 
what  glass  is  to  light — 
comparatively  transpar- 
ent. Loud,  on  the  con- 
trary, being  heavy, 
comparatively  opaque 


I'iir.  26.  Radiograph 
power  of  the  rays  to  penetrate  matter  de- 
pends on  the  density.  The  strips  A,  B 
and  Care  platinum,  aluminum  and  paper 
respectively.  It  is  easy  to  see  that  the 


is 


platinum  is  penetrated  least. 


As  a  matter  of  fact,  they 
obey  the  law  of  absorp- 
tion, page  72  (Part  III),  and  in  this  they  resemble  the  cor- 
of  the  cathode  rays  (Fig.  26). 
(96) 


THE  BECQUEREL  RAYS  FROM  RADIUM.        97 
PHOTOGRAPHIC  POWER. 

In  their  power  to  take  radiographs,  Becquerel  rays  from 
radium  resemble  X-rays  (Fig.  27) .    A  radiograph  of  a  purse 


Fig.  27.     Radiograph  by  the  Curies.     A  pinch  of  radium  was  used  at 
a  distance  of  a  foot.     Time,  1  hour. 

was  taken  in  the  dark  by  exposing  the  plate  with  the  purse 
upon  it  to  the  invisible  Becquerel  rays  for  one  hour.  It  has 
all  the  characteristics  of  an  X-ray  picture. 

.       PHOSPHORESCENCE. 

Many  substances  when  they  are  exposed  to  Becquerel  \ 
rays  shine  in  the  dark — that  is  they  phosphoresce.    The  dia-  1 
mond  and  the  ruby  shine  out  vividly  on  being  held  up  in  the 
invisible  rays  emitted  by  a  pinch  of  chloride  of  radium.     So 
do  fluorspar,  calcium  sulphide,  barium  platino-cyanide,  and 
many  others.     So  powerful  is  the  phosphorescence  caused  by 
Becquerel  rays  that  if  a  tube  of  radium  bromide  be  held  to 
the  forehead,  and  the  experimenter  close  his  eyes,  he  will 
still  see  light.    The  retina  itself  becomes  phosphorescent. 
7 


93 


THE  NEW  KNOWLEDGE. 


They  even  strike  backward  upon  the  radium  substance  it- 
self, so  that  it,  too,  becomes  luminous,  and  shines  vividly 
with  a  light  which,  since  the  discovery  of  radium,  has  shown 
no  shadow  of  variableness.  Becquerel  rays  by  means  of  this 
self-phosphorescence  will  photograph  the  radium  which  emits 
them.  Fig.  28  (a)  is  a  picture  of  some  radium  chloride 
photographed  by  daylight,  and  Fig.  28  (6)  shows  the  same 
radium  chloride  photographed  in  the  dark  by  its  own  light 
—a  life-size  portrait  of  the  first  radium  chloride  in  the  world 
executed  by  itself.  They  seem  strange  things,  then,  these 


Fig.  28  (a). 

Radium  chlo- 
ride photo- 
graphed by 
daylight,  by 
M.  Curie. 


Fig.  28  (b). 
Radium  chlo- 
ride photo- 
graphed in 
dark  by  the 
light  of  its 
own  phos- 
phorescence. 


[To  obtain  the  wonderful  photographs  shown  in  Fig.  28  (a  and  b}, 
less  than  y$5  of  a  gram  of  chemically  pure  radium  chloride  was  utili/ed 
by  M.  Curie.  The  value  of  a  grain  of  i.ulinin  would  be  $10,000  or  more. 
Less  than  a  gram  exists.] 

Becquerel  rays  from  radium  and  yet  strange  as  they  are, 
in  this  power  of  causing  phosphorescence  in  bodies  which 
they  strike,  they  exactly  resemble  the  corpuscles  of  cathode 
rays,  page  69,  Part  III. 


THE    BECQUEREL    RAYS   FKo.M    RADIUM. 


99 


PHYSIOLOGICAL   EFFECT. 

The  physiological  effect  of  Becquerel  rays  from  radium  is 
most  intense — almost  incredible.  A  pinch  of  radium  salt, 
contained  in  a  sealed  glass  tube  was  placed  in  a  cardboard 
box,  which  was  then  tied-  to  the  sleeve  of  Professor  Curie  for 
an  hour  and  a  half.  An  intense  inflammation  resulted, 
followed  by  a  suppurating  sore  which  took  more  than  three 
months  to  heal.  Professor  Becquerel,  as  he  went  about  his 
work  one  day,  chanced  to  carry  a  sealed  glass  tube  of  radium 
salt  in  his  pocket,  placed  there  for  convenience.  He  was 
sorry,  for  the  sore  was  painful  and  most  tedious  in  healing. 
Becquerol  rays  from  radium  will  cause  paralysis  in  mice  and 
caterpillars  subjected  to  their  action,  and  diluted  to  a  suffi- 
cient degree  bid  fair  to  exercise  a  decidedly  curative  effect 
upon  human  ills.  In  their  physiological  action  they  re- 
semble markedly  the  X-rays  of  Rontgen. 

ELECTRICAL    EFFECTS. 

Photographic  plates  and  electrified  bodies  are  widely  dif- 
ferent. Yet  Becquerel  discov- 
ered at  about  the  same  time 
that  they  were  both  affected  by 
his  rays.  A  photographic  plate 
was  blackened;  an  electrified 
body  was  discharged;  either 
was  a  detector  of  radio-activity. 
With  the  discovery  of  radium, 
the  discharging  effect  became, 
of  course,  exceedingly  apparent. 
Fig.  29  (a)  is  an  electroscope 
with  its  little  gold  leaves  spread 
apart  by  electrification.  On  the 
approach  of  a  glass  tube  con- 


Fig.  29  (a). 


100 


THE   NEW  KNOWLEDGE. 


taining  a  tiny  amount  of  radium  chloride,  the  leaves  at 
once  collapse  through  the  discharge  of  their  electrification, 
Fig.  29  (b).  The  approach  of  radium  and  the  discharge 

of  the  leaves  are  simul- 
taneous. Investigation 
showed  that  the  effect 
was  due  to  the  fact  that 
the  rays  emitted  by  the 
radium  spontaneously 
rendered  the  air  a  con- 
ductor of  electricity,  and 
naturally  the  electrifica- 
tion of  the  leaves  flew 
away  with  as  much  ease 


Fig.  29  (6). 


as  if  they  had  been  touched  by  a  copper  wire.  As  a  mat- 
ter of  fact,  an  electrified  body  is  a  more  sensitive  detector 
of  radio-activity  than  a  photographic  plate.  In  this  prop- 
erty of  discharging  electrified  bodies  the  Becquerel  rays  are 
identical  with  positive  ions,  corpuscles  and  X-rays. 

CHEMICAL   EFFECT. 

Becquerel  rays  cause  chemical  action.  Emitted  from 
radium  they  will  discolour  paper,  cause  glass  to  take  a  violet 
tint,  turn  oxygen  into  ozone,  yellow  phosphorus  into  red 
phosphorus,  mercury  perchloride  into  calomel  and  will 
decompose  iodoform.  In  the  power  of  causing  chemical 
action,  they  resemble  both  the  corpuscles  in  cathode  rays 
and  X-rays. 

THE  SECRET  OF  THE  BECQUEREL  RAYS. 

We  have  learned  how  Becquerel  discovered  his  rays,  we 
have  studied  some  of  their  properties,  and  we  arc  now  face 
to  face  with  the  problem,  most  important  of  all.  What  are 
they? 


THE  BECQUEREL  RAYS  FROM  RADIUM. 


101 


In  their  study  so  far,  we  have  discovered  no  property  not 
shared  by  the  positive  ions,  corpuscles  or  X-rays  emitted  by 
candle  flames,  hot  wires  or  Crooks'  tubes  as  elucidated  in 
Part  III.  Can  it  be  that  Becquerel  rays  are  identical  with 
these  bodies?  And  if  so,  which?  Fortunately  they  have 
one  more  strange  property  which  Becquerel  discovered  them 
to  possess,  and  which,  as  it  turns  out,  affords  a  master  key  to 
their  nature. 

BECQUEREL  RAYS  ARE  BEXT  BY  A  MAGXET. 

Becquerel  proved 
this  by  one  of  his 
characteristic  fec- 
und, simple  exper- 
iments. Taking  a 
narrow  phot  o- 
graphic  plate  en- 
veloped in  black 
paper,  he  placed  it 
horizontally  be- 
tween the  poles  of 
a  powerful  electro- 
magnet (Fig.  30). 
On  the  black  en- 
velope of  the  plate 
he  then  placed  a 
little  lead  trough 
containing  a  small 
amount  of  the  ra- 
dium compound. 
The  rays  could  thus 


Fig 


M  Becquerel  and  the  experiment 
with  the  magnet. 

affect  the  plate  only  by  bending  over,  for  the  lead  is  opaque. 
He  energized  the  magnet;   then  after  a  certain  time,  he  re- 


102 


THE   NEW   KNOWLEDGE. 


l\  tk 


versed  the  polarity,  thinking  that,  if  the  rays  bent  at  all, 
they  would  bend  in  the  opposite  direction.  Fig.  31  is  the 
answer — clear  as  sunlight.  The  plate  shows 
two  broad  bands,  proving  that  the  rays  must 
have  been  curved  clown  to  meet  it;  that 
there  are  two  bands  instead  of  one  proves 
that  reversing  the  polarity  causes  the  rays  to 
bend  in  the  opposite  direction.  Becquerel 
rays  are  deviable  by  a  magnet.  But  are  they 
all  equally  deviable?  Are  they  homogene- 
ous? Upon  another  plate  of  the  same  kind 
he  placed  strips  of  platinum,  aluminum  and 
paper,  and  at  the  end  of  the  plate,  as  before, 
the  little  lead  trough  containing  the  radium 
compound.  If  they  were  all  equally  devi- 
able, they  would  form  a  line  when  they  bent 
to  meet  the  plate ;  if  not,  they  would  form  a 
band.  After  energizing  the  magnet  and  de- 
ij  veloping  the  plate,  he  obtained  the  result 
•  *  shown  in  Fig.  32.  The  rays  are  not  equally 


Fig.  31.         they  form 

The  magnetic  ,  . 

deviation      of    "       1)r°ad 

Becquerel    band,       a 

Rays.  veritable 

spectrum,  of  an  infinity 
of  rays  unequally  (levi- 
able. The  same  plate  Fig.  32.  Radiograph  showing  how  the 
shows  as  well  that  the  power  of  the  rays  to  penetrate  matter  de- 
rays  penetrate  the  pends  on  the  density.  The  strips  A,B 

and  Care  platinum,  aluminum  and  paper 

screens    in    this    order:    respectively.    It  is  easy  to  set  that  the 

the    platinum  least,    the     platinum  is  penetrated  I 

aluminum  next,  and  the  paper  most  of  all.    Are  they  all 


THE    BECQUEREL   RAYS   FROM   RADIUM.  103 

deviable?  Is  it  not  possible  that  some  of  them  are  totally 
unaffected  by  the  magnet,  and  do  not  bend  at  all?  To  find 
out,  why  not  place  the  narrow  photographic  plate  vertically, 
instead  of  horizontally,  between  the  poles  of  the  magnet. 
The  idea  was  carried  out,  and  the  result  is  plain  beyond  all 
question.  The  Becquerel  rays  consist  of  at  least  two  kinds 
of  radiation.  One  kind,  A  (Fig.  33),  is  bent  by  the  magnet; 


Fig.  33. 

the  other,  B,  is  apparently  unaffected  by  it,  and  passes  un- 
deviatingly  on.     The  print  (Fig.  34)  taken  under  the  mag- 


Fig.  34. 

net,  shows  still  more  clearly  the  existence  of  two  distinct 
kinds  of  radiation.     With   these   two  kinds  of  radiation 


104  THE   NEW  KNOWLEDGE. 

science  for  a  time  remained  content,  and,  indeed,  in  error; 
for,  as  it  turned  out,  Professor  Rutherford  was  finally  able  to 
show  that,  by  the  application  of  magnetic  forces  transcend- 
ently  strong,  part  of  the  so-called  undeviable  beam  could, 
as  a  matter  of  fact,  be  to  a  slight  extent  deviated  but  in  the 
opposite  direction  from  the  deviable  portion  already  known, 
while  the  other  part  remained  still  absolutely  undeviable. 
Furthermore,  it  turned  out  that  this  truly  undeviable  portion 
of  the  beam  of  rays  possessed  a  penetrative  power  to  an  ex- 
tent simply  extraordinary,  producing  an  appreciable  effect 
on  a  photographic  plate  through  a  foot  thickness  of  solid 
iron!  By  means  of  the  magnetic  effect  we  have  thus  been 
able  to  analyze  the  Becquerel  rays  from  radium  into  three 
distinct  types  or  kinds  of  radiation: 

(1)  Rays  that  have  very  little  penetrative  power  and  are 
only  slightly  bent  by  the  strongest  magnetic  forces  obtain- 
able.    These  are  known  as  the  alpha-rays. 

(2)  Rays  that  are  very  penetrating  in  character  and  are 
easily  bent  by  weak  magnetic  forces  in  a  direction  opposite 
to  that  of  the  alpha-rays.    Those  rays  are  known  as  the 
beta-rays. 

(3)  Rays  that  are  absolutely  undeviable  by  the  strongest 
magnetic  force  obtainable  and  have  an  unexampled  power 
of  penetrating  matter  generally  considered  opaque.    These 
are  the  gamma-rays. 

All  these  three  types  of  rays,  it  must  be  remembered  are 
continuously  given  off  by  radium  compounds  in  their  nat- 
ural condition  without  any  diminution  whatever  so  far  as 
has  yet  been  detected.  We  have  now  all  the  data  nec- 
essary for  answering  with  a  reasonable  degree  of  confidence 
the  question :  What  are  the  alpha-,  the  beta-  and  the  gam- 
ma-rays from  radium? 


CHAPTER  VI. 
THE  ALPHA-,  BETA-  AND  GAMMA-RAYS.  , 

THE  ALPHA-RAYS. 

The  secret  of  the  alpha-rays  drops  into  our  hands  as  soon 
as  we  compare  them  in  their  properties  with  the  positive 
ions  of  Part  III.  The  positive  ions,  as  we  learned,  were 
tiny  bodies  laden  with  positive  electrification  flying  off, 
under  certain  conditions,  from  gas  flames,  red-hot  metals 
and  other  bodies.  We  learned  that  their  velocities  were 
anywhere  from  ten  to  twenty  thousand  miles  a  second,  that 
their  mass  was  about  twice  that  of  a  hydrogen  atom  and  4- ; 
that  on  the  application  of  intense  magnetic  force  they  could 
be  slightly  bent  or  deviated.  Now  the  alpha-rays  from 
radium  have  properties  identical  with  those  stated  above. 
They  are  the  positive  ions,  but  instead  of  requiring  high 
temperatures  or  other  exceptional  conditions  for  their  exist- 
ence they  fly  off  from  the  substance  radium  in  its  natural 
normal  state.  On  the  basis  of  all  the  evidence  necessary 
to  convince  a  reasonable  man,  the  alpha-rays  from  radium 
are  streams  of  little  bodies  with  a  mass  about  twice  the  mass  v'  ^  < 
of  the  hydrogen  atom  flying  off  from  radium  and  laden  with 
positive  electricity.  Their  velocity  is  about  20,000  miles  a 
second!  Compare  this  velocity  with  that  of  the  swiftest 
projectile  that  man  can  fire  from  a  gun.  A  rifle  bullet 
travels  with  a  velocity  of  about  half  a  mile  a  second,  and 
we  consider  this  speed  of  transit  extreme,  but  these  pro- 
jected atoms  have  a  velocity  40,000  times  greater.  Now 
the  energy  of  any  moving  body  increases  as  the  square  of 

(105) 


106  THE    NEW   KNOWLEDGE. 

its  velocity     (Energy^-);  and  hence  the  energy  carried 

off  from  radium  by  these  little  flying  bullets  is  almost  in- 
credibly large  compared  with  their  mass.  As  Professor 
Rutherford  says:  "If  it  were  possible  to  give  an  equal  ve- 
locity to  an  iron  cannon  ball,  the  heat  generated  by  the  im- 
pact on  a  target  would  be  many  thousand  times  more  than 
sufficient  to  melt  the  cannon  ball  and  dissipate  it  into 
vapour."  This  is  the  conclusion  of  mathematical  reasoning, 
but  no  amount  of  reasoning  is  half  so  demonstrative  to  the 
average  mind  as  the  sight  of  a  fragment  of  radium  at  work. 
We  have  stated  that  the  mere  presence  of  radium  will  cause 
certain  substances  in  the  neighbourhood  to  phosphoresce  or 
to  light  up  with  a  glow.  Now  among  the  substances  af- 
fectablc  by  radium  there  is  one,  zinc  sulphide,  which  answers 

to  the  bombardment  of  the 

CJ 

C  alpha-rays      alone.       This 

property  has  been  utilized 
,-'A   by  Sir  William  Crookes  in 
the  construction  of  a  little 
instrument    which    he    has 
called     a     sphinthariscope, 
which  shows  beautifully  the 
bombardment  of  the  alpha- 
r     3r)  rays.    This  instrument  con- 

Section  of  Crookes'  Spinthariscope,    sists  of  a  small  fragment  of 
T— The  outer  containing  tube.  radium  placed  behind  a  zinc 

T,T— The  diding  tube,  for  focussing.   sulphi<lo     screen,     which     is 
A — The   screen,   coated  inside    with      .          ,  .      ..        ,     ,     ,, 

klen,l(i  viewed  in  the  dark  through 

B— The  wire  supporting  the  speck  a  tube  containing  a  magni- 
P1  "f  r;"ln""  >llf  fying  eyepiece  (Fig.  35).    At 

C— The  magnifying  1,-ns.  J       »    J 

once  one seesa  thousand  tiny 
Hashes  of  light,  for  the  spark  of  each   atomic  projectile  as 


THE  ALPHA-,  BETA-  AND  GAMMA-  RAYS.       107 

it  strikes  the  zinc  sulphide  target  is  at  once  made  visible 
to  the  eye.  The  appearance  is  that  of  a  swamp  full  of  fire- 
flies, or  the  scintillating  stars  on  a  clear  night.  And  when 
one  remembers  that  these  flashes  of  light  are  caused  by  a 
rain  of  projectiles,  each  impact  being  marked  by  a  flash  of 
light,  just  as  sparks  fly  off  from  iron  when  it  is  struck  by  a 
hammer,  and,  moreover,  that  this  rain  of  projectiles  is  in- 
cessant, day  in  and  day  out,  year  in  and  year  out,  the 
wonder  becomes  most  impressive  that  the  radium  should 
not  soon  dissipate  itself  by  this  continuous  projection  of 
matter.  The  number  of  atoms,  however,  in  the  small  mass 
of  radium  is  so  enormous  that  the  process  will  probably 
continue  several  hundred  years  before  an  appreciable  part 
of  the  radium  has  disappeared.  Becquerel  has  recently 
brought  forward  evidence  to  show  that  the  light-flashes  ob- 
served are  due  to  cleavages  produced  in  the  zinc  sulphide 
crystals  by  the  impact  of  the  alpha  particles. 

THE  BETA-RAYS. 

These  have  been  the  most  widely  studied  of  the  rays 
from  radium,  owing  to  their  great  penetrating  power  and 
their  action  in  exciting  phosphorescence  in  bodies  which 
they  strike.  It  is  hardly  necessary  to  tell  the  reader,  form- 
ally, what  they  are.  Suppose  we  construct  a  table  of  com- 
parison between  the  beta-rays  from  radium  and  the  corpus- 
cles from  candle  flames  and  hot  metals.  Let  us  make  X 
equal  the  possession  of  any  one  specific  property  possessed 
by  both  in  equal  decree. 


108 


THE   NEW  KNOWLEDGE. 


Comparison  between  Beta-rays  and  Corpuscles. 


Property. 

Beta-rays. 

Corpuscles. 

They  are  negatively  electrified  particles. 

X 

X 

Velocity. 

10,000  to 
90,000  miles 
por  second. 

75,000    to 
150,000  miles 
per  second. 

The  same  electrical  charge  as  a  hydrogen 
atom. 

X 

X 

They  have  a  mass  equal  to  one  one-thou- 
sandth of  a  hydrogen  atom. 

X 

X 

They  discharge  electrified  bodies. 

X 

X 

They  are  deflected  by  a  magnet  in  the 
opposite  direction  from  the  alpha-rays 
and  positive  ions. 

X 

X 

They    are    deflected    by    an    electrostatic 
force. 

X 

X 

They    cause    phosphorescence    in    bodies 
wnich  they  strike. 

X 

X 

They  give  rise  to  heat  in  bodies  which  they 
strike. 

X 

X 

They  communicate  mechanical  motion  to 
bodies  which  they  strike. 

- 

X 

They  give  rise  to  X-rays  in  bodies  which 
they  strike. 

X  (?) 

X 

They  are  absorbed  by  all  bodies  in  direct 
proportion  to  their  density. 

X 

X 

They  act  as  nuclei  about  which  atoms  and 
molecules  collect. 

X 

X 

We  see  from  the  table  above  that  the  one  and  only  differ- 
ence between  the  corpuscles  of  candle  flumes  and  Crooke's 


THE    ALPHA-,    BETA-   AND    GAMMA-   RAYS.  109 


tubes,  and  the  beta-rays  from  radium  is  one  of  velocity. 
The  beta-rays  fly  faster,  for  they  reach  the  enormous  average 
velocity  of  more  than  one  hundred  thousand  miles  a  second. 
We  have  here,  not  an  analogy  nor  a  similarity,  but  an  identity. 
The  beta-rays  from  radium  are  corpuscles,  for  they  possess 
the  same  properties  and  in  the  same  degree  within  the  limits 
of  experimental  error.  What  a  wonder,  then,  have  we  here  ; 
an  innocent  looking  little  pinch  of  white  salt  not  so  different 
in  its  general  properties  from  ordinary  table  salt  and  yet 
possessed  of  special  properties  utterly  beyond  even  the 
fanciful  imaginings  of  men  of  past  time;  for  nowhere  do  we 
find  in  the  records  of  thought  even  the  hint  of  the  possibility 
of  things  which  we  now  regard  as  established  fact.  This 
pinch  of  salt  projects  from  its  surface  bodies  possessing  the 
inconceivable  velocity  of  over  100,000  miles  a  second,  a 
velocity  sufficient  to  carry  them,  if  unimpeded,  five  times 
around  the  earth  in  a  second,  and  possessing  with  this  ve- 
locity masses  a  thousand  times  smaller  than  the  smallest 
atom  known  to  science.  Furthermore,  they  are  charged  with 
negative  electricity;  they  pass  straight  through  bodies  con- 
sidered opaque  with  a  sublime  indifference  to  the  properties 
of  the  body,  with  the  exception  of  its  mere  density;  they 
cause  bodies  which  they  strike  to  shine  out  in  the  dark ;  they 
affect  a  photographic  plate;  they  render  the  air  a  conductor 
of  electricity;  they  cause  clouds  in  moist  air;  they  cause 
chemical  action  and  have  a  peculiar  physiological  action. 
Who,  to-day,  shall  predict  the  ultimate  service  to  humanity 
of  the  beta-rays  from  radium ! 

THE   GAMMA-RAYS. 

The  gamma-rays  from  radium  are  still  to  a  certain  extent 
a  mystery.  Unlike  the  alpha-  and  the  beta-rays  they  can- 
not be  bent  by  a  magnet,  and  their  most  remarkable  prop- 


110  THE   NEW   KNOWLEDGE. 

erty  consists  apparently  in  their  power  of  penetrating 
matter  generally  considered  opaque.  They  will  pass 
through  a  foot  of  solid  iron  or  through  several  inches  of 
metallic  lead.  They  seem  to  be  neutral  electrically,  and 
they  are  seemingly  the  agent  chiefly  concerned  in  the  phys- 
iological action  of  radium.  They  also  affect  a  photographic 
plate.  They  appear  to  be  X-rays,  or  at  least  some  type 
of  X-rays.  In  our  study  of  the  properties  of  corpuscles 
(Part  III)  we  learned  that  whenever  corpuscles  of  a  Crookes' 
tube  struck  against  a  metal  plate  or  the  walls  of  the  glass 
containing  vessel,  X-rays  were  developed;  and  that,  in 
fact,  an  ordinary  X-ray  bulb  was  nothing  but  a  tube  in 
which  corpuscles  were  generated.  If  the  beta-rays  from 
radium  are  in  solid  truth  the  corpuscles  of  Part  III,  it  is 
natural  to  expect  that  they  should  generate  X-rays  in 
their  back-stroke  as  they  left  the  radium,  and  consequently 
it  should  be  no  matter  of  surprise  to  find  in  the  gamma- 
rays  nothing  but  X-rays  as  a  natural  accompaniment  to  the 
corpuscles.  While  the  gamma-rays  are,  therefore,  in  their 
nature  probably  nothing  but  X-rays  it  is  at  this  time  not 
positively  certain.  Of  course,  the  identity  of  the  gamma- 
rays  with  X-rays  does  not  tell  us  what  the  gamma-rays  are 
in  themselves  unless  we  know  the  nature  of  the  X-rays,  and 
in  the  X-rays  we  have  still,  more  or  less,  a  mystery.  X  is 
an  unknown  quantity.  It  is  probable  that  they  are  not  a 
'form  of  matter,  that  is,  that  they  are  not  particles  at  all, 
but  more  in  the  nature  of  pulses  or  waves  in  the  sur- 
rounding ether  set  up  by  the  impact  of  the  corpuscles  or 
beta-rays.  It  is  natural  and,  indeed,  inevitable  that  the 
vibrations  of  corpuscles  should  disturb  the  surrounding 
ether  into  waves  just  as  shaking  a  stick  in  water  must  set 
up  water  waves,  or  as  the  grosser  atoms  of  matter  set  up 
the  etherial  waves  of  heat  and  light.  And  it  is  also  natu- 


THE    ALPHA-,    BETA-   AND    GAMMA-   RAYS.  Ill 

ral  enough  that  these  waves  set  up  by  corpuscular  vibrations 
should   be  very  different   in  properties  from  those  arising 
from  the  vibration  of  grosser  atoms.     It  is  probable  that  » 
the  X-rays  are  due  to  ethereal  vibration,  not  material  par-  / 
tides,  and  that  the  gamma-rays  from  radium  are  X-rays.   1 

We  have  thus  found  in  the  alpha-,  beta-  and  gamma-rays  . 
from  radium  the  positive  ions,  corpuscles  and  X-rays  of 
Part  III,  their  natural  progenitors  in  the  history  of  discov- 
ery. "What  an  anti-climax,"  says  the  reader.  "We 
started  out  to  study  a  new  property  of  matter,  and  here 
we  end  up  with  an  old  one."  Not  a  bit  of  it.  We  called 
the  new  property  of  matter  radio-activity — not  Becquerel 
rays.  "  What  is  the  difference  ? "  All  the  difference  be- 
tween a  natural  intrinsic  property  and  a  property  of  con- 
dition. The  light  of  an  arc-lamp  is  a  property  of  condition; 
suppose  you  found,  deep  in  the  earth,  some  natural  substance 
blazing  forever  with  a  light  as  great,  that  would  be  a  natu- 
ral intrinsic  property — and  a  very  curious  one — radio- 
activity. So  with  the  positive  ions,  the  corpuscles  and 
the  X-rays  of  Part  III.  They  arise  from  candle  flames, 
red-hot  metals,  or  electrified  vacuum  tubes,  all  of  them 
substances  or  mechanisms  under  very  special  conditions. 
The  Becquerel  rays  from  radium,  on  the  contrary,  arise 
from  a  substance  dug  out  of  the  ground  which  will  emit 
them,  apparently,  for  centuries  in  the  future  as  it  has 
emitted  them  apparently  through  the  countless  centuries 
of  the  past,  without  any  extrinsic  influence.  It  is  their 
natural  intrinsic  property — a  new  property  of  matter — 
radio-activity. 

Part  III  taught  us  the  existence,  under  special  condi- 
tions, of  bodies  a  thousand  times  smaller  than  the  smallest 
atom.  Part  IV,  so  far,  has  taught  us  the  natural  emission 
of  such  particles  from  a  substance  in  its  normal  state. 


CHAPTER  VII. 
EMANATIONS. 

Having  thus  analyzed  the  rays  from  radium  into  three 
different  kinds  apparently  identical  with  the  positive  ions, 
corpuscles  and  X-rays,  it  may  seem  to  the  reader  that  we 
have  now  explained  the  whole  mystery  of  radium  in  terms 
of  what  we  already  know.  But  this  is  far  from  being  the 
case.  The  mystery  of  radium  is  still  a  mystery  as  beau- 
tiful and  fascinating  as  ever.  Let  us  now  consider  one  more 
remarkable  property  of  radium  which  opens  up  a  new  world 
of  wonders.  Professor  and  Madame  Curie  have  discovered 
that  any  substance  placed  near  radium  becomes  itself  a 
false  radium.  "  We  have  found,"  say  the  Curies,  "that  any 
substance  placed  in  the  neighbourhood  of  radium  acquires  a 
radio-activity  which  persists  for  many  hours,  and  even  days, 
after  the  removal  of  the  radium.  This  induced  radio-ac- 
tivity increases  with  the  time  during  which  it  is  exposed 
to  the  action  of  the  radium  up  to  a  certain  limit.  After 
the  radium  is  removed,  it  decreases  rapidly,  and  tends  to 
disappear.  The  kind  of  substance  exposed  to  the  action 
of  the  radium  is  almost  a  matter  of  indifference.  They  all 
acquire  a  radio-activity  of  their  own.77  This  fact  has  been 
verified  over  and  over  again  by  every  experimenter  in  the 
field.  The  zinc,  iron  and  lead  fittings,  the  air  of  the  labo- 
ratory, the  water,  the  clothing  of  the  workers,  their  very 
persons,  in  the  presence  of  radium,  start  into  activity  and 
give  out  rays  comparable  to  radium  in  affecting  a  photo- 
graphic plate  and  discharging  electricity.  This  becomes 
(112) 


KM.  \\ATIONS.  113 

very  vexatious  and  disconcerting  and  extreme  care  is  neces- 
sary to  prevent  the  radium  giving  out  rays  altogether  mis- 
directed. For  days  Professor  Curie  was  unable  to  approach 
his  electrometers  or  even  to  enter  his  laboratory,  owing 
to  his  acquired  radio-activity.  These  secondary  radiations, 
in  the  case  of  zinc,  were  four  times  as  intense  as  ordinary 
uranium.  Moreover,  this  acquired  radio-activity  cannot  be 
removed  by  washing.  It  must  be  remembered,  however, 
that  the  radio-activity  is  only  temporary.  It  vanishes 
sooner  or  later  upon  the  removal  from  the  neighbourhood 
of  the  potent  radium.  Fig.  36  is  a  photograph  taken  in 


Fig.  36.     Phosphorescence  induced  by  induced  radio-activity. 

Professor  Curie's  laboratory,  of  phosphorescent  action 
caused  by  these  induced  secondary  radiations.  It  was  ob- 
tained in  the  following  way :  Two  samples  of  zinc  sulphide, 
A  and  B,  and  a  sample  of  a  salt  of  uranium,  C,  were  placed 
in  cardboard  pillboxes,  and  these  were  laid  on  a  metallic 
plate,  under  which  was  the  radium  chloride.  The  metallic 
plate  was  quite  thick  enough  to  be  opaque  to  the  Becquerel 
rays,  but  under  their  influence  it  gave  off  secondary  radi- 
ations which  caused  the  salts  within  the  pill-boxes  to  phos- 
8 


114 


THE   NEW  KNOWLEDGE. 


phoresce.  The  photographs  were  taken  from  above.  They 
were  caused  by  the  induced  light  of  induced  radio-activity. 
We  have  used  the  word  "  induced  "  here  as  descriptive  of 
this  secondary  or  acquired  radio-activity  because  it  was 
at  first  Professor  Curie's  opinion,  as  it  was  nearly  every- 
body's else,  that  bodies  in  the  neighbourhood  acquired 
this  temporary  and  secondary  radio-activity  because  of  the 
mere  presence  of  the  radium,  in  the  same  way  that  iron 
filings  become  magnetic  in  the  presence  of  a  magnet  or  as 
the  induced  electric  currents  arise  in  an  induction  coil. 
Some  facts,  however,  soon  became  apparent,  that  have  al- 
tered completely  this  conception  of  the  nature  of  the  ac- 
quired radio-activity.  For  example,  Professor  and  Ma- 
dame Curie  performed  the  following  experiment  :  Two 
small  flasks  were  connected  together  by  a  lateral  tube  fused 
into  their  necks  (Fig.  37),  and  having  a  stop-cock  in  the 


Fig.  37. 

tube  joining  them;  the  cock  being  closed,  a  solution  of  the 
radio-active  substance  was  passed  into  one  of  the  flasks, 
while  a  gelatinous  white  precipitate  of  sulphide  of  zinc, 


EMANATIONS.  115 

which  it  is  to  be  remembered,  is  phosphorescent  to  the  ac- 
tion of  radium  rays,  was  placed  in  the  other  flask;  then 
both  flasks  were  closed.  So  long  as  the  cock  between  the 
flasks  remains  closed,  nothing  is  visible  in  the  dark;  but 
the  instant  it  is  opened,  the  sulphide  of  zinc  becomes  bril- 
liantly phosphorescent  and  continues  so  as  long  as  the  tube 
connecting  the  flasks  remains  open.  Now  we  cannot  believe 
that  either  the  alpha-,  the  beta-  or  the  gamma-rays  from 
radium  have  the  power  to  pass  around  a  corner  as  they 
would  necessarily  do  in  order  to  pass  from  flask  to  flask  to 
cause  the  zinc  sulphide  to  phosphoresce.  In  fact  we  know 
they  do  not,  and  Ii3nce  we  must  believe,  for  there  is  no 
other  way  out  of  it,  that  a  something  more  or  less  in  the 
nature  of  a  gas,  and  not  these  rays  at  all,  must  pass  from 
flask  to  flask;  and  since,  moreover,  this  something  causes 
the  zinc  sulphide  to  shine  in  the  dark,  we  must  also  be- 
lieve that  it  is  radio-active.  Now  this  radio-active  some- 
thing which  passes  out  of  radium  and  which  is  a  some- 
thing distinct  and  apart  from  the  rays  themselves  has  been 
called  an  emanation.  It  is  called  an  emanation  rather 
than  a  gas  because  Rutherford,  its  original  discoverer,  was 
not  sure  that  it  was  a  gas.  It  is  apparently  the  cause 
of  this  induced  radio-activity  acquired  by  all  bodies  in  the 
neighbourhood  of  radium,  for  spreading  out  from  the  ra- 
dium it  settles  on  surrounding  objects  and  renders  them 
radio-active.  Having  settled,  then,  the  fact  of  a  radio- 
active something  spreading  out  from  radium  independent 
of  the  straight  line  radiations  of  the  alpha-,  beta-  and 
gamma-rays,  it  is  of  extreme  importance  to  find  out  what 
it  is.  Here,  then,  are  some  experiments,  which  one  after 
another  elucidates,  to  some  extent,  the  nature  of  the  emana- 
tion. 
First,  let  us  remember  that  wlii'tlr.T  it  is  a  gas  or  not,  it 


116  THE   NEW   KNOWLEDGE. 

acts  like  one  in  continuously  diffusing  into  the  surrounding 
air  and  that,  moreover,  by  passing  a  current  of  air  over  the 
radium  it  may  be  carried  away  like  an  ordinary  gas,  and 
that  the  air  so  permeated  by  it  continues  to  give  off  rays 
long  after  its  passage  over  the  radium.  Next  it  became  ob- 
vious that  the  amount  of  emanation  given  off  by  it  in  the  solid 
cold  state  was  insignificant  compared  to  the  veritable  rush 
emitted  on  heating  the  radium  salt  or  on  dissolving  it  in 
water.  This  also  is  quite  in  accord  with  the  supposition 
that  it  is  a  gas  of  some  kind  occluded  or  hidden  away  in  the 
radium.  This  latter  method,  that  of  solution,  is  the  best 
method  of  obtaining  the  emanation  for  purposes  of  study. 
A  small  quantity  of  radium  chloride  is  dissolved  in  water 
and  the  rush  of  emanation  is  collected  by  bubbling  air 
through  the  solution  and  carrying  off  the  air  so  permeated 
with  the  emanation  into  an  ordinary  gas-holder,  where  it  will 
light  up  a  screen  of  phosphorescent  zinc  sulphide  for  days 
and  will  show  some  radio-activity  even  after  the  lapse  of  a 
minute.  On  passing  this  ray-emitting  air  containing  the 
emanation  from  the  gas-holder  over  platinum,  palladium, 
zinc,  magnesium  and  lead  chromate,  all  at  an  intense  red 
heat,  it  was  found  impossible  to  alter  the  ray-emitting  power 
to  any  sensible  degree.  The  ray-emitting  power  of  the 
emanated  air  is  absolutely  conserved.  No  ordinary  gas 
could  withstand  the  action  of  the  powerful  reagents  speci- 
fied above  and  hence  we  are  obliged  to  assume  that  if  it  is 
a  gas,  and  it  seems  to  be,  the  emanation  must  belong  to 
that  interesting  family  of  inert  gases  discovered  by  Rayleigh 
and  Ramsay  in  the  atmosphere,  which  are  known  as  helium, 
neon,  argon,  krypton  and  xenon  and  which  the  reader  will 
find  tabulated  in  the  zero  group  of  the  periodic  law  and 
discussed  in  Part  II.  The  probability  that  the  emanation 
is  an  actual  gas  is  greatly  emphasized  by  the  fact  that  it 


EMANATIONS. 


117 


may  be  condensed  from  the  air  with  which  it  is  mixed  by 
the  action  of  extreme  cold.  The  radium  emanation  con- 
denses on  the  glass  walls  of  the  vessels  into  a  brilliant  patch 
of  phosphorescent  light  at  150  degrees  below  zero,  Centi- 
grade. If,  therefore,  it  behaves  in  all  these  respects  like  an 
ordinary  gas  the  reader  may  wonder  why  it  should  not  be 
definitely  called  a  gas,  but  the  difficulty  of  it  is  that  the 
emanation  exists  in  so  minute  a  quantity  that  it  has  not 
yet  been  brought  within  the  range  of  the  spectroscope  or 
the  balance.  The  emanation  has  been  detected,  and  in- 
vestigated by  the  electroscope  [Figs.  38  (a)  and  38  (6)],  which 


Fig.  38  (a).  Fig.  38(6). 

Curie's  Electroscope  for  the  Diagrammatic  representation  of 

study  of  radio-activity.  Fig.  38  (a). 

An  electroscope  will  detect  one  one-millionth  of  a  millionth  of  a  milligram. 

measures  the  radium  rays  by  the  power  to  discharge  its 
electrified  gold  leaves.  The  electroscope  is  about  a  mil- 
lion times  more  sensitive  than  the  most  sensitive  spectro- 
scope and  yet  the  spectroscope  is  capable  of  detecting  easily 
the  millionth  part  of  a  milligram  of  matter.  So  it  is  that 
history  repeats  itself.  The  spectroscope,  wrhen  placed  new 


118  THE    NEW   KNOWLEDGE. 

in  the  hands  of  science,  revealed  the  existence  of  several  ele- 
ments occurring  in  quantities  too  small  to  be  detected  by 
any  other  means.  In  a  similar  way  additional  elements 
have  now  been  detected  and  isolated  by  this  more  powerful 
instrument,  the  electroscope,  which  for  years  has  been  the 
toy  of  every  high  school  laboratory.  There  is  every  proba- 
bility that  when  greater  quantities  of  radium  are  at  the  dis- 
posal of  the  investigator  the  radium  emanation  will  be 
collected  in  quantity  sufficient  to  demonstrate  clearly  its 
spectrum  as  an  element  and  its  vapour  pressure  as  a  gas. 
The  amount  of  energy  radiated  by  the  emanation  is  almost 
incredibly  large  compared  with  the  small  amount  of  matter 
involved.  We  have  said  that  the  emanation  from  a  grain 
or  two  of  radium  chloride  when  liberated  by  solution  is  ca- 
pable of  illuminating  brightly  a  screen  of  phosphorescent 
zinc  sulphide  for  days  at  a  time,  and  yet  this  rapid  emission 
of  energy  arises  from  a  quantity  of  gaseous  matter  hundreds 
of  thousands  of  times  beyond  the  power  of  the  most  delicate 
balance  to  detect.  Professor  Rutherford  has  calculated  that 
if  a  thimbleful  of  this  active  gas  could  be  collected  the 
bombardment  of  its  powerful  rays  wrould  heat  to  a  red  heat, 
if  it  would  not  melt  clown,  the  walls  of  the  glass  tube  con- 
taining it  !  This  remarkable  fact  leads  naturally  to  two 
very  important  questions: 

(1)  What  is  the  nature  of  the  rays  emitted  by  the  emana- 
tion?   Are  they  alpha-,  beta- or  gamma-rays;  or,  to  use  the 
terminology  of  Part  III,  are  they  positive  ions  as  big  as 
atoms,  corpuscles  a  thousand  times  smaller  than  atoms,  or 
X-rays? 

(2)  What  becomes  of  the  radium  from  which  the  emana- 
tion has  been  removed,  the  de-emanated  radium?     Has  it 
lost  any  of  its  radio-activity,  what  kind  of  rays  does  it  still 
emit? 


EMANATIONS.  119 

For  the  first  question  the  answer  is  ready.  The  emana- 
tion emits  only  alpha-rays,  bodies  positively  electrified  as 
big  as  atoms. 

For  the  second  question,  the  answer  is  also  ready.  The 
radium  from  which  the  emanation  has  been  extracted  has 
lost  about  seventy-five  per  cent,  of  its  activity,  and  the  rays 
which  it  does  still  emit  after  the  lapse  of  an  hour  or  so  are, 
again,  only  alpha-rays.  Leaving  for  the  present  the  ques- 
tion as  to  what  becomes  of  the  beta-  and  gamma-rays,  we 
are  now  face  to  face  with  possibly  the  most  remarkable,  the 
most  interesting  and  the  most  illuminating  fact  in  connec- 
tion with  all  this  strange  eventful  history  of  the  nature  of 
radium.  We  have  said  that  the  emanation  abstracted  from 
the  radium  retained  its  ray-emitting  power  for  some  time. 
The  obvious  inference  is  that  it  eventually  loses  its  power 
completely.  It  does.  We  have  also  said  that  the  radium 
from  which  the  emanation  has  been  abstracted,  after  the 
lapse  of  an  hour  or  so,  loses  seventy-five  per  cent,  of  its  ac- 
tivity. This  also  is  true.  But  wait  a  month,  and  the  most 
remarkable  fact  crops  out  that  the  radium,  during  the  inter- 
val, has  restored  all  its  lost  emanation  and  has  fully  regained 
its  activity.  The  interesting  phase  of  the  fact  lies  in  the 
further  discovery  that  the  emanation  abstracted  from  the  radium  i 
loses  its  radio-activity  at  the  same  rate  and  according  to  the} 
same  laws  as  the  de-emanated  radium  regains  it.  A  perfectly 
clear  demonstration  of  this  is  given  in  the  diagram  (Fig.  39), 
in  which  the  curve  A  represents  the  actual  rate  of  recovery 
of  the  radium  activity  and  curve  B  the  rate  of  decay  of  the 
radium  emanation.  The  illuminating  phase  of  the  fact  lies 
in  its  inferences.  If,  as  is  apparently  the  case,  the  radium 
is  constantly  generating  and  storing  the  emanation  and  the 
emanation  as  constantly  decaying,  the  activity  of  the  radium 
at  any  one  time  is  due  to  a  balance  between  the  decaying 


120 


THE   NEW   KNOWLEDGE. 


and  restoring  processes;  and  since,  moreover,  these  processes 
are  wholly  outside  the  sphere  of  known  controllable  forces, 
and  cannot  be  created,  altered  or  destroyed — since  the  process 
is  independent  of  the  chemical  form  of  the  radium,  whether 
bromide,  chloride,  sulphate,  etc., — we  are  absolutely  shut 
up  to  the  conviction  that  it  is  a  function  of  its  atom.  We 
are  in  the  presence  of  a  veritable  decay  of  the  atom.  The 
atom  of  radium  breaks  down  into  atoms  of  emanation  and 


Fig.  39. 

the  atoms  of  emanation  in  their  turn  break  down  into  some- 
thing else.  The  activity  of  the  emanation  decays  in  ac- 
cordance with  the  curve  given  in  Fig.  39,  and  falls  to  half 
value  in  about  3.^  days.  This  has  rendered  it  possible  to 
calculate  that  there  should  be  463,000  times  as  much  emana- 
tion stored  hi  the  solid  as  is  formed  per  second.  Now,  on 
dissolving  the  radium  in  water  all  this  emanation  should  bo 
spontaneously  emitted  in  a  rush,  and  this  rush  of  emanation 


EMANATIONS.  121 

can  be  measured  by  an  electroscope  and  the  figures  stated 
above  put  to  the  test.  This  was  done,  and  it  was  discovered 
as  a  matter  of  fact  that  the  amount  of  emanation  stored  in 
the  solid  was  477,000  times  greater  than  the  amount  after- 
wards developed  per  second.  The  agreement  between  theory 
and  experiment  is  remarkable  and  the  experiment  shows 
just  how  accurately  it  is  possible  to  predict  the  results  of  ex- 
periments in  radio-activity. 


CHAPTER  VIII. 
EMANATION  X  AND  THE  BIRTH  OF  HELIUM. 

In  addition  to  the  power  of  giving  off  the  alpha-rays  or 
positive  ions  possessed  by  the  emanation,  it  has  the  ad- 
ditional very  remarkable  property  of  exciting  activity  in 
any  substance  with  which  it  comes  in  contact.  This  is  the 
induced  radio-activity  discovered  by  Curie.  This  activity 
of  surrounding  objects  not  otherwise  radio-active  is  due  to 
the  fact  that  the  emanation  in  decaying  breaks  down  into 
a  third  invisible  and  unweighable  radio-active  body  which 
deposits  itself  upon  neighbouring  bodies  and  which,  appar- 
ently, is  in  the  nature  of  a  solid.  Surrounding  objects  thus 
become  radio-active.  This  "  excited  "  activity,  since  it  is 
evolved  from  and  results  in  the  decay  of  the  emanation  has 
been  called  emanation  X.  The  emanation  X  has  definite 
chemical  properties  for  it  can  be  dissolved  in  some  acids 
and  not  in  others.  If  the  acid  in  which  the  emanation  X 
is  dissolved  be  evaporated  it  is  left  behind  on  the  dish  and 
its  radio-activity  is  unimpaired.  It  has  recently  been  dis- 
covered that  this  emanation  X  may  be  volatilized  at  a 
white  heat  and  re-deposited  on  cold  bodies  in  the  neighbour- 
hood, making  them  radio-active.  It  is  not  the  emanation 
for  the  rate  of  decay  of  its  activity  is  markedly  different 
from  the  rate  of  decay  of  the  emanation.  It  is  a  second 
form  of  active  matter  generated  from  radium  via  the  ema- 
nation. It  is  this  form  of  matter  that  gives  rise  to  the  beta- 
and  gamma-rays  which  are  emitted  from  the  solid  radium 
compound  and  which  we  failed  to  find  either  in  the  emana- 
(122) 


!•:  MA  NATION    X  AND   THE   BIRTH    OF   HELIUM.  123 

tion  or  in  the  radium  from  which  the  emanation  had  been 
removed.  The  emanation  X  emits  alpha-rays  as  well,  and 
it  is  therefore  probable  that  it,  in  its  turn,  breaks  down  into 
two  other  forms  giving  rise  to  the  beta-  and  gamma-rays 
respectively,  but  we  have  now  reached  the  last  link  in  the 
chain  of  consequences  which  result  from  the  decay  of  ra- 
dium. The  instruments  of  the  physicist,  refined  though 
they  are,  refuse  to  take  him  farther.  The  radio-activity 
of  radium  may  be  explained  to  this  extent.  The  solid 
radium  compound  is  continuously  giving  off  energy,  in  the 
form  of  alpha-,  beta-  and  gamma-rays.  Of  this  energy  25 
per  cent,  belongs  to  the  radium  itself,  consists  of  alpha- 
rays,  and  may  not  be  removed.  Of  the  remaining  75  per 
cent.  18  per  cent,  belongs  to  the  emanation  proper  and  con- 
sists also  of  alpha-rays ;  while  the  residue  of  the  energy,  57 
per  cent.,  belongs  to  the  emanation  X,  and  the  final  products 
and  consists  of  all  three  types  of  rays.  To  the  emanation  X 
the  solid  active  body  produced  by  the  emanation  and  capable 
of  settling  on  other  bodies  the  major  part  of  the  energy  from 
radium  must  thus  be  ascribed.  In  a  solid  radium  compound, 
therefore,  all  three  bodies,  the  regenerating  radium,  the  de- 
caying emanation  gas  and  the  solid  emanation  X  exist  to- 
gether; and  the  total  activity  of  the  radium  is  due  at  any 
one  instant  to  a  balance  between  the  qualities  and  activi- 
ties of  the  three  bodies  therein  contained.  A  question 
must  now  suggest  itself  to  the  reader.  What  is  the  end  of 
this  chain  of  consequences?  What  is  the  final  product 
formed  in  the  decay  of  radium?  Surely  some  evidence  of 
it  must  exist.  Xow,  some  twenty-five  years  ago,  Sir  Nor- 
man Lockyer  discovered  that  there  exist  >  in  enormous 
quantities  in  the  atmosphere  of  the  sun  a  certain  element 
which,  because  it  was  not  then  known  on  earth,  was  named 
after  its  habitat — helium,  or  the  sun  element.  Twenty 


124  THE   NEW   KNOWLEDGE. 

years  after  its  discovery  on  the  sun  it  was  identified  by  Sir 
William  Ramsay  as  a  constituent  of  certain  minerals  in  the 
earth's  surface.  Its  discovery  both  in  the  sun  and  in  the 
earth  depends  upon  the  fact  that  the  element  has  a  peculiar 
characteristic  spectrum  (Fig.  40).  It  turned  out  to  belong 
to  the  Argon  series  of  elements,  those  elements  which 
the  reader  will  find  tabulated  in  the  zero  group  of  the 
periodic  law  (page  28),  and  which  are  all  alike  in  the  fact 
that  they  are  gases  incapable  of  entering  into  chemical  com- 
bination and  in  this  respect  are  different  from  all  other  ele- 
ments. It  is  a  very  remarkable  fact  that  this  gas,  helium,  as 
found  on  earth  is  always  associated  with  radio-active  min- 
erals; and  it  soon  occurred  to  many  minds  that  possibly  it 
was  a  product  of  the  atomic  disintegration  of  the  radium. 
A  few  months  ago  this  was  the  merest  speculation  but  now, 
thanks  to  the  rapid  progress  of  science,  it  looks  as  though  it 
were  a  veritable  fact.  The  discovery  arose  in  the  following 
way :  Sir  William  Ramsay  and  Mr.  Soddy  in  the  summer  of 
1903,  were  examining  with  the  spectroscope  the  air  which 
had  been  bubbled  through  a  solution  of  radium  bromide  in 
order  to  find  whether  or  not  it  was  possible  to  discover  any 
traces  of  a  spectrum  of  the  emanation,  which,  the  reader 
will  remember,  is  obtained  in  that  way.  They  did  discover 
some  bright  lines  which  they  ascribed  to  the  emanation,  but 
after  standing  for  some  time  the  spectrum  of  helium  made 
its  appearance  and  increased  in  brightness  for  several  days. 
This  indicates  that  the  helium  is  produced  from  the  ema- 
nation; that  is  to  say  that  helium  is  a  disintegration  prod- 
uct of  the  radium  emanation.  It  is  possible  that  the 
helium  consists  of  the  alpha-rays  or  positively  electrified 
particles  given  out  by  the  emanation.  The  fact  that  the 
mass  of  the  alpha  particle  is  about  twice  that  of  the  hydro- 
gen  atom  bears  out  that  idea,  for  the  helium  atom  is  next 


EMANATION   X  AND   THE   BIRTH   OF  HELIUM.  125 

to  hydrogen  to  lightness.  However  that  may  be,  if,  as 
seems  to  be  the  case,  helium  is  produced  from  the  radium 
decomposition,  the  world,  in  this  experiment,  has  witnessed 
the  greatest  triumph  of  modern  science — no  more  nor  less 
than  the  transmutation  of  matter.  The  dream  of  the  al- 
chemists is  true.  Whether  helium  is  the  final  product  of 
the  radium  disintegration,  or  a  by-product  from  the  emana- 
tion, is  to-day  unknown. 


Fig.  40.     The  five  characteristic  bright  lines  of  the  spectrum  of  helium. 

We  may  now  sum  up  the  series  of  radio-active  changes 
in  radium  by  the  following  tabulation,  remembering  that 
between  the  emanation  X  and  the  final  product  there  prob- 
ably exists  several  intermediate  forms,  and  that  somewhere 
hi  the  chain  helium  appears. 

Radium  containing  25  per  cent,  of  non-separable  activity 
in  the  form  of  alpha-rays. 

Radium  emanation  containing  18  per  cent,  of  the  activ- 
ity in  the  form  of  alpha-rays. 

Radium  emanation  X  containing  57  per  cent,  of  the  to- 
tal activity  as  alpha-,  beta-  and  gamma-rays. 

Final  product  inactive. 


CHAPTER  IX. 
THORIUM,  URANIUM,   POLONIUM  AND  ACTINIUM. 

While  radium  seems,  to-day,  to  be  the  radio-active  ele- 
ment par  excellence,  radio-activity  is  not  confined  to  ra- 
dium. Among  the  other  radio-active  elements,  thorium  is 
important.  Thorium  is  a  comparatively  rare  element,  and 
is  the  fundamental  constituent  of  nearly  all  the  Wclsbach 
gas  mantles  used  for  lighting.  Its  radio-activity  is  ex- 
ceedingly small  compared  with  that  of  radium,  but  small 
as  it  is,  it  is  in  some  respects  more  interesting  even  than 
that  of  radium.  All  thorium  compounds  are  radio-active. 
All  thorium  compounds  give  off  alpha-,  beta-  and  gamma- 
rays — but,  after  this  is  said,  the  resemblance  between  ra- 
dium and  thorium  ceases.  The  radio-activity  of  radium 
remains  constant  no  matter  how  drastic  the  treatment  to 
which  it  is  subjected.  The  radio-activity  of  thorium  is 
not  constant.  In  fact  it  has  been  found  possible  by  chemi- 
cal processes  to  separate  out  nearly  all  its  activity  and  to 
concentrate  it  afterwards  into  a  minute  quantity  of  in- 
tensely active  matter. 

If  ammonia  is  added  to  a  solution  of  thorium,  the  tho- 
rium is  precipitated  in  the  form  of  a  solid  and  so  sepa- 
rated from  the  water  in  which  it  was  dissolved.  But  the 
water  now  retains  the  activity  of  the  thorium  and  the 
precipitated  thorium  has  lost  it.  On  evaporating  this 
water  solution  down  to  dryness  and  igniting  it,  a  small 
residue  of  intensely  active  matter  remains  which  turns 
out,  weight  for  weight,  to  be  over  a  thousand  times  more 
(126) 


THORIUM,    URANIUM,    POLONIUM  AND  ACTINIUM.        127 


active  than  the  thorium  from  which  it  was  extracted. 
This  small  quantity  of  very  active  matter  has  been  called 
by  the  discover,  Rutherford,  thorium  X.  On  examining 
the  thorium  X  and  the  precipitated  thorium  a  month 
later,  the  astonishing  result  became  evident  that  the  tho- 
rium X  had  completely  lost  its  activity  while  the  thorium 
had  wholly  regained  it;  furthermore  it  was  discovered  that 
the  rate  of  decay  of  the  thorium  X  was  exactly  equal  to 
the  rate  of  recovery  of  the  thorium.  This  fact  is  demon- 
strated in  the  diagram  (Fig.  41)  in  which  the  actual  curves 


40 


\ 


//?  O  7</S  ~ 


12.  (6 

Fig.  41. 


24 


of  decay  and  recovery  are  given.  The  only  conceivable 
explanation  of  this  fact  lies  in  the  somewhat  extraordinary 
proposition  that  the  element  thorium  is  constantly  generat- 
ing from  itself  another  solid  element,  which  decays  at  the 
same  rate  at  which  it  is  generated.  The  radio-activity  of 
thorium  is  due  to  a  balance  between  two  opposing  forces 
which  are:  (1)  the  radio-activity  resulting  from  the  manu- 


128  THE  NEW  KNOWLEDGE. 

facture  of  thorium  X,  and  (2)  the  decay  of  the  activity 
of  the  thorium  X,  so  produced.  Here  again  is  a  transmuta- 
tion of  matter!  We  are  not  however  at  the  end  of  this 
process  of  change,  for  it  turns  out  that  this  thorium  X  in 
decaying,  decays  into  an  emanation  similar  in  character  to 
the  emanation  from  radium  but  not  identical  with  it.  Both 
the  radium  and  thorium  emanation  give  rise  to  alpha-rays 
only,  but  while  the  radium  emanation  condenses  on  the 
walls  of  the  glass  vessel  at  150  degrees  below  zero  Centi- 
grade, the  thorium  emanation  condenses  at  120  degrees 
below;  furthermore  the  activity  of  the  radium  emanation 
decays  to  half  value  in  3.7  days,  while  the  thorium  emana- 
nation  from  thorium  X  decays  to  half  value  in  one  min- 
ute. The  two  emanations  are  therefore  not  identical, 
though  they  are  both  unaffected  by  the  most  drastic 
methods  of  chemistry  and  seem  to  belong  to  the  same 
chemical  family.  The  thorium  emanation  gives  rise  to  an 
emanation  X  just  as  in  the  case  of  radium.  This  emana- 
tion settles  on  the  walls  of  the  containing  vessel  apparently 
with  the  form  of  a  solid  and  emits  all  three  radiations, 
alpha-,  beta-  and  gamma-rays.  As  with  radium  emanation, 
it  is  soluble  in  some  acids  and  not  in  others,  but  it  is  no 
more  identical  with  radium  emanation  X  than  thorium  is 
identical  with  radium — just  as  with  the  two  emanations  the 
time  rates  of  decay  of  activity  in  the  two  emanations  X 
are  different. 

Finally,  as  with  radium,  the  thorium  emanation  X  decays 
into  some  end  product  which  does  not  possess  ray-emitting 
powers  and  which  the  instruments  of  to-day  are  unable  to 
determine.  The  main  difference  between  the  radio-activity 
of  radium  and  thorium  seems  to  lie  chiefly  in  a  difference  in 
intensity  and  in  the  fact  that  thorium  breaks  down  into  a 
radio-active  solid  intermediate  between  the  thorium  and  the 


THORIUM,    URANIUM,    POLONIUM    AND    ACTINIUM.        129 

thorium  emanation.  No  similiar  radium  X  has  yet  been 
discovered.  The  radio-activity  of  a  solid  thorium  salt  is 
then  due  to  the  radio-activity  of  the  thorium,  the  thorium 
X,  the  emanation,  and  the  emanation  X,  all  condensed 
within  it. 

THE   RADIO-ACTIVITY  OF  URANIUM. 

Uranium  was  the  first  element  discovered  to  possess 
radio-activity,  the  power  of  continuously  emitting  pene- 
trating rays.  Since  radium  was  extracted  from  uranium 
minerals,  it  was  at  first  imagined  that  the  activity  of  ura- 
nium was  due  to  radium  impurity.  This  was  a  mistake. 
The  radio-active  power  of  uranium,  however,  is  very  small ; 
1,500,000  times  less  than  pure  radium.  It  possesses,  how- 
ever, a  special  interest  in  the  fact  of  its  simplicity.  Like 
thorium,  and  unlike  radium,  it  continuously  gives  rise  to  a 
solid  disintegration  product,  uranium  X,  though  this  differs 
from  thorium  X  in  emitting  beta-  instead  of  alpha-rays. 
The  uranium  from  which  the  uranium  X  has  been  extracted 
emits  only  alpha-rays.  Just  as  in  all  radio-active  processes, 
the  decay  of  the  activity  of  the  uranium  X  and  the  revival 
of  the  activity  of  the  pure  uranium  take  place  at  the  same 
rate,  so  that  the  activity  of  a  uranium  compound  at  any  one 
instant  is  due  to  a  balance  between  the  opposing  forces  of 
decay  and  restoration.  Half  of  this  process  of  decay  and 
restoration  takes  place  in  twenty-two  days.  Unlike  both 
radium  and  thorium  the  uranium  X  gives  rise  to  no  emana- 
tion and  consequently  to  no  emanation  X.  As  a  result  of 
this  fact  bodies  in  the  neighbourhood  do  not  become  radio- 
active. The  active  uranium  X  decays,  apparently,  directly 
into  some  inactive  product.  Uranium  has  been  used  to 
test  the  constancy  of  radio-active  processes.  For  over  five 
years  the  activity  of  a  sample  of  uranium  has  been  tested  at 
9 


130  THE   NEW  KNOWLEDGE. 

intervals  of  48  hours  and  during  this  interval  no  perceptible 
weakening  of  the  radiation  has  been  observed.  A  varia- 
tion of  one  one-hundredth  thousandth  of  its  activity  would 
have  been  apparent — a  singular  example  of  the  constancy 
of  radio-activity  and  the  powers  of  radio-active  methods. 

POLONIUM. 

Polonium  was  first  extracted  from  the  mineral  pitchblende 
by  Mde.  Curie  and  named  in  honour  of  her  native  country, 
Poland.  It  is  chemically  a  sister  to  bismuth,  from  which  it 
has  never  been  satisfactorily  separated.  A  most  minute 
quantity,  only,  has  been  obtained  for  experimentation.  Po- 
lonium is  intensely  active  but  differs  from  other  radio-active 
elements  in  giving  rise  to  alpha-rays  only.  Furthermore, 
its  activity  seems  to  decrease  with  time,  a  result  quite  out 
of  concord  with  the  activity  of  the  other  elements. 

Prof.  Markwald  has  recently  succeeded  in  extracting 
what  seems  to  be  the  same  substance  by  another  method. 
The  "  polonium  "  obtained  by  him  is  intensely  active.  A 
minute  trace  on  the  end  of  a  rod  will  cause  a  diamond  to 
phosphoresce  brightly  and,  indeed,  may  be  used  to  distinguish 
the  diamond  from  imitations.  The  activity  of  polonium  is 
so  great  that  an  electric  bell  will  ring  at  its  mere  approach  for 
it  renders  the  air  in  its  neighbourhood  a  strong  conductor  of 
electricity.  Owing  to  the  minute  traces  as  yet  isolated, 
knowledge  of  polonium  is  in  a  chaotic  condition ;  but  since 
its  activity  seems  greater  even  than  radium  it  bids  fair  to 
be  an  important  factor  in  future  research. 

ACTINIUM. 

Another  radio-active  element  discovered  in  Prof.  Curie's 
laboratory  has  been  called  actinium.  Chemically  it  re- 
sembles thorium  but  its  activity  is  many  thousands  of  times 


THORIUM,    URANIUM,   POLONIUM  AND   ACTINIUM.      131 

greater.  Like  radium  and  thorium,  it  gives  rise  to  an  in- 
tensely active  emanation  which,  however,  loses  its  activity  in 
a  few  seconds.  A  minute  quantity  only  has  been  extracted, 
but  it  has  been  sufficient,  nevertheless,  to  demonstrate  its 
powerful  radiations.  A  piece  of  paper  placed  in  the  same 
vessel  with  a  trace  of  actinium  becomes  in  a  short  time 
radiantly  active  and  is  capable  of  lighting  up  a  screen  of 
zinc  sulphide  by  its  mere  presence. 

These  then  are  the  radio-active  elements  :  radium,  tho- 
rium, uranium,  polonium,  and  actinium.  Each  one  has 
properties  which  differentiate  it  from  all  the  others. 

We  append  a  tabular  statement  of  the  main  radio-active 
changes  which  uranium,  thorium,  and  radium  undergo,  to- 
gether with  some  of  the  properties  of  the  changing  bodies. 


132 


THE    NEW   KNOWLEDGE. 


Radio-active  bodies. 

Properties  of 
active  matter 
undergoing 
change      per 
«econd. 

Time  taken 
for   half    oi 
body         to 
undergo 
change. 

Kind     of 

Hays. 

alpha 

beta 
(and 

liannna?) 

Chemical      and 
physical     prop- 
erties. 

Uranium 

i, 

Uranium  X 

* 

Final  product 

30 

22  days 

Soluble    in    ex- 
cess   of    ammo- 
nium carbonate. 

Insoluble  in  ex- 
cess   of    ammo- 
nium carbonate. 

100,000,000 

Thorium 

1 

Thorium  X 

I 

Thorium  emanation 

1 

Emanation  X 
(first  change) 

1 

Second  change 

I 

Final  product 

2 

4  days 
1  minute 

55  minutes 
11  hours 

alpha 

alpha 
(and 
beta?) 

alpha 

no    rays 

alpha, 
beta  and 
gamma 

Soluble   in   am- 
monia. 

Soluble    in  am- 
monia. 
Behaves   like   a 
chemically  inert 
gas     of     heavy 
molecular 
weight,         con- 
denses at—  1200 
C. 
Attaches     itself 
to    the    surface 
of  bodies. 
Soluble  in  some 
acids  and  not  in 
others. 

1,000,000 
115 

10,000 
22 

100,000 
174 

10,000,000 

Radium 

1 

Radium  emanation 

1 

Emanation  X 
(first  change) 

* 

Second  change 

J 

Third  change 

I 

Fourth  change 

1 

Final  product 

211 

3'7  to  4  days 

about  3 
minutes 

36  minutes 
28  minutes 
200  years? 

alpha 
alpha 
alpha 

no  rays 

alpha, 
beta  and 
gamma 
alpha 
and  beta 

Behaves   like  a 
chemically  inert 
gas.    Condenses 
at—  1500  C. 

Attaches     itself 
to    the    surface 
bodies. 
Soluble  in  some 
acids  and  not  in 
others. 

Soluble    in   sul- 
phuric acid. 

100,000,000 
4 

1,000 
318 

1,000,000 
41 

100,000 

CHAPTER  X. 
RADIO-ACTIVITY  EVERYWHERE. 

Radio-activity  is  not  confined  to  the  radio-active  elements. 
It  exists  everywhere  though  in  minute  degree.  The  air  of 
cellars  and  caves  is  markedly  radio-active.  So  is  the  air 
sucked  up  from  the  soil,  and  particularly  clay.  The  air 
of  the  free  atmosphere,  normal  air,  is  slightly  radio-active. 

A  wire  strongly  electrified  and  suspended  in  the  air  for  a 
few  hours  acquires  a  strong  ray-emitting  power  which  may 
be  rubbed  off  and  transferred  to  leather  moistened  with 
ammonia. 

Freshly  fallen  rain  and  snow  are  radio-active.  Air 
bubbled  through  the  Cambridge  tap-water  emits  rays;  so 
does  the  surface  water  of  New  Haven,  Connecticut,  and 
air  boiled  off  from  the  mineral  springs  at  Bath.  Natural 
carbonic  acid  arising  from  great  depths  of  old  volcanic 
soil  has  been  tested  and  found  active,  and  so  has  the  fine 
mud  from  the  mineral  springs  of  Northern  Italy  and  the  air 
of  the  Baltic  coast.  Everywhere  over  the  earth  there  seems 
to  arise  an  emission  of  penetrating  rays.  For  the  most  part 
these  rays  seem  to  be  due  to  the  presence  of  small  quanti- 
ties of  radium  contained  in  the  earth  and  permeating  the 
atmosphere  with  its  emanation.  But  is  it  all  due  to  this  ? 
Are  we  sure  that  all  matter  is  not  to  some  slight  extent 
radio-active  ?  Many  ordinary  substances  certainly  do  show 
radio-activity.  Thus,  tin-foil,  glass,  silver,  zinc,  lead,  cop- 
per, platinum  and  aluminum,  all  of  them  are  slightly  radio- 
active. Shall  we  account  for  this  on  the  ground  that  they 

(133) 


134  THE   NEW   KNOWLEDGE. 

all  contain  small  quantities  of  the  strong  radio-active  ele- 
ments as  an  impurity,  or  that  it  is  the  natural  intrinsic 
property  of  all  matter  to  emit  rays  ? 

That  important  question  is  for  the  future  to  decide.  Of 
one  thing  we  may  be  certain :  If  all  forms  of  matter  pos- 
sess the  power  of  emitting  rays  they  do  so  to  an  exceed- 
ingly minute  degree.  Radio-activity,  as  we  are  accustomed 
to  consider  it,  seems  to  be  par  excellence  the  property  of 
the  heavy  atom  of  matter.  And  if  in  the  future  new  heavy 
atoms  are  discovered  we  may  safely  predict  for  them,  as 
an  intrinsic  property,  the  possession  of  radio-activity. 


PART  V. 


THE  KESOLUTION  OF  THE  ATOM. 


PART  V. 
THE  RESOLUTION  OF  THE  ATOM. 


CHAPTER  I. 

MODERN  ALCHEMY:  THE  TRANSMUTATION  OF  MATTER. 

Amid  the  shifting  scenes  wherein  they  live,  men  have 
always  believed  in  the  existence  of  an  underlying  reality  or 
unity  of  which  the  ordinary  changing  forms  of  matter  are 
but  a  superficial  manifestation. 

"  There  abides  in  nature  a  certain  form  of  matter  which 
being  discovered  and  brought  by  art  to  perfection,  converts 
to  itself  all  imperfect  bodies  that  it  touches."  This  is  a 
saying  of  the  ancient  alchemy,  and  it  constitutes  a  prop- 
osition from  the  rooted  belief  in  which  have  sprung  many 
centuries  of  sweaty,  toilsome,  futile  effort. 

"  In  chemistry  we  recognize  how  changes  take  place  in 
combinations  of  the  unchanging."  This  is  the  statement 
of  chemistry,  the  daughter  of  alchemy. 

The  two  forms  of  statement  are  alike  in  this,  that  they 
postulate  an  underlying  essence  of  simplicity  and  perfectness. 

With  the  alchemist  this  simplicity  lay  in  a  certain  sub- 
stance. Commonly,  it  was  called  the  philosopher's  stone 
and,  later,  the  elixir  of  life.  By  means  of  it,  if  one  could  but 
come  at  it,  it  was  possible,  at  a  touch  to  transmute  all 
baser  metals  into  gold  and,  by  drinking  it,  to  gain  eternal 
life  on  earth. 

(137) 


138  THE  NEW  KNOWLEDGE. 

The  possibility  of  transmuting  one  metal  into  another 
seemed  entirely  reasonable  to  medieval  men,  and,  taking 
their  point  of  view,  it  was  reasonable.  They  were  imbued 
with  the  idea  of  growth  and  change.  They  saw  that  plants 
and  animals  grew  from  one  form  into  another  and,  if  so, 
why  not  metals? 

Here  is  something  of  the  argument  between  Subtle  and 
Surly  in  old  Ben.  Johnson's  "  Alchemist,"  in  which  Subtle 
is  endeavoring  to  persuade  Surly  of  the  transmutability  of 
the  metals  and,  incidentally,  to  cozen  him  out  of  his  money. 

Subtle :   No  egg  but  differs  from  a  chicken  more 

Than  metals  in  themselves. 
Surly:    That  cannot  be. 

The  egg's  ordained  by  nature  to  that  end, 

And  is  a  chicken  in  potentia. 
Subtle :  The  same  we  say  of  lead  and  other  metals, 

Which  would  be  gold  if  they  had  time. 

for  'twere  absurd 

To  think  that  nature  in  the  earth  bred  gold, 
Perfect  in  the  instant;  something  went  before. 
There  must  be  remote  matter." 

.  This  remote  matter  was  of  course  the  philosopher's  stone 
which  Subtle  was  about  to  prepare  at  Surly's  expense.  The 
lines  in  which  Subtle  concludes  his  argument  are  interesting: 

"  Besides,  who  doth  not  see  in  daily  practice 
Art  can  beget  bees,  hornets,  beetles,  wasps, 
Out  of  the  carcasses  and  dung  of  creatures; 
Yea,  Scorpions  of  an  herb,  being  rightly  placed  ? 
And  these  are  living  creatures,  far  more  perfect 
And  excellent  than  metals." 


MODERN   ALCHEMY.  139 

If  "art  can  beget  bees.  .  .  .  out  of  the  carcasses  and 
dung  of  creatures/7  why,  the  production  of  gold  out  of 
lead  ought  to  be,  in  comparison,  a  simple  task,  for,  cer- 
tainly, a  bee  is  a  more  complicated  structure  than  a  metal. 
But  Surly  is  proof  against  the  subtleties  of  Subtle,  and 
says: 

"  That  alchemy  is  a  pretty  kind  of  game 
Somewhat  like  tricks  o'  the  cards,  to  cheat  a  man 
With  charming;"  and  so,  in  truth  it  was; 

That  wonderful  transmuting  stone  still  evaded  the  mind 
and  hand  of  man  to  find. 

The  years  rolled  on ;  alchemy  glided  into  chemistry,  and 
the  search  for  the  one  simple  perfect  thing  capable  of  trans- 
muting by  its  touch  one  element  into  another  became  itself 
transmuted  into  the  study  of  "  how  changes  take  place  in 
the  combinations  of  the  unchanging, — the  unchanging  things 
being  what  the  chemists  called  the  elements  of  matter,  gold, 
iron,  copper  and  the  like.  The  alchemists,  fanatics,  knaves, 
or  knavish-fanatics,  gave  place  little  by  little  to  investigat- 
ing men  of  another  type,  keen-minded,  accurate,  and  con- 
servative in  their  judgments;  pre-eminently,  men  who  did 
not  believe  in  fairy-tales.  Robert  Boyle  in  1681  in  the  title 
of  his  book  "  The  Skyptical  Chymist"  defines,  in  general, 
the  character  of  all  succeeding  chemists,  for  "  skyptical " 
they  have  always  been,  beyond,  even,  the  followers  of  any 
other  science.  Beginning  with  Boyle,  these  men  gradually 
displaced  the  alchemical  "simple,  perfect  essence"  by  a 
thorough-going  belief  in  the  existence  of  from  seventy  to 
eighty  elements  which  they  found  it  impossible  to  break 
down  into  simpler  bodies,  and  out  of  which  in  their  various 
combinations  the  world  of  matter  is  made.  These  elements 
were  undecomposable,  unchanging,  simple  things.  It  is  true 


140  .  THE   NEW   KNOWLEDGE. 

that  chemists  were  always  careful  to  guard  their  definition 
by  the  statement  that  the  elements  were  undecomposable 
so  Jar  as  they  could  do,  and  simple  so  far  as  they  could  see, 
but  the  underlying  assumption  of  two  hundred  years  of 
chemists  was  that  the  elements  were  simple,  unchanging 
bodies.  Gold  was  gold  and  iron  was  iron,  and  any  attempt 
to  make  them  other  than  themselves  was  the  proper  func- 
tion of  the  men  of  a  thousand  years  hence.  Of  course,  there 
were  men  who  divined  rather  than  reasoned  that  this  sim- 
plicity and  unchangingness  were  apparent  rather  than  real. 
Thus,  in  1811  we  find  Davy  saying  "  It  is  the  duty  of  the 
chemist  to  be  bold  in  pursuit.  ...  He  must  recollect  how 
contrary  knowledge  sometimes  is  to  what  appears  to  be  ex- 
perience. ...  To  inquire  whether  the  metals  be  capable 
of  being  decomposed  and  composed  is  a  grand  object  of 
true  philosophy."  Again,  in  1815,  Faraday  uses  similar 
terms  when  he  says:  "To  decompose  the  metals,  to  reform 
them,  and  to  realize  the  once  absurd  notion  of  transmuta- 
tion, are  the  problems  now  given  to  the  chemist  for  solu- 
tion." But  these  were  voices  crying  in  the  wilderness  and 
the  possibility  of  the  transmutation  of  one  element  into  an- 
other was,  on  the  part  of  everybody,  deemed  as  absurd  as 
the  existence  of  the  philosopher's  stone  which,  to  the  al- 
chemists, was  to  accomplish  the  work. 

We  have  now  to  present  to  the  reader  some  remarkable 
facts:  Let  us  leave,  for  the  "|once,  all  talk  of  atoms,  ions 
and  corpuscles,  and  the  mysterious  rays  of  radium,  to  con- 
sider in  a  simple  way  some  straightforward  matters  of  fact 
connected  with  radio-activity.  We  are  dependent  for  these 
"  facts"  on  the  men  who  enunciate  them;  but  if  these  men 
are  men  of  light  and  loading,  if  they  command  the  respect 
of  all  their  confreres,  and  if  they  occupy  positions  of  the 
highest  honour  and  responsibility  in  the  world  of  science  we 


MODEHX    ALCHEMY.  141 

must  have  faith  in  their  "  facts."  Such  are  the  men  upon 
whose  ipse  dixit  the  facts  of  the  science  of  radio-activity 
mainly  rest.  They  are  distinctly  men  of  credibility.  Hav- 
ing confidence,  then,  in  their  statements  of  fact  let  us  ex- 
amine into  them. 

We  discover  that  there  exists  in  nature  a  certain  well- 
known  "  element,"  uranium.  This  element  is  radio-active; 
that  is,  it  has  the  power  of  continuously  emitting  rays. 
These  rays  are  of  two  kinds:  one,  the  positively  electrified 
and  slightly  penetrating  alpha-rays,  and  the  other  the  highly 
penetrating  and  negatively  electrified  beta-rays. 

By  methods  of  chemical  fractionation  somewhat  similar 
to  that  by  which  radium  is  isolated  from  pitchblende, 
it  has  been  found  possible  to  separate  from  this  uranium 
another  substance  altogether;  and,  furthermore,  it  turns 
out  that  this  separated  substance  is  entirely  responsible  for 
the  beta-rays  of  the  original  uranium,  the  substance  from 
which  it  was  extracted  giving  rise  only  to  the  alpha-rays. 
The  extracted  substance  is  known  as  uranium  X.  This  fact 
is  followed  by  another.  The  extracted  uranium  X  gradually 
but  completely  loses  its  power  of  emitting  the  beta-rays, 
and  at  such  a  rate  that  half  of  it  has  disappeared  in  about 
22  days;  while,  on  the  contrary,  the  uranium  from  which  it 
has  been  extracted  regains  this  power  at  the  very  same 
rate,  and  eventually  becomes  as  potent  as  ever.  After  it 
has  been  restored  you  may,  if  you  like,  extract  a  second 
quantity  of  uranium  X,  and  a  third,  and  a  fourth,  and  so 
on,  so  far  as  is  known,  ad  infinitum.  This  is  a  matter  of 
fact  into  which  no  theory  enters.  On  the  basis  of  this 
fact,  then,  we  seem  compelled  to  conclude  that  the  uranium 
is  continuously  manufacturing  from  itself  another  substance, 
uranium  X,  which  has  only  a  transitory  existence;  and 
that  the  power  of  emitting  these  penetrating  rays,  which  an 


142  THE  NEW  KNOWLEDGE. 

ounce  of  any  uranium  compound  at  any  time  possesses,  is 
due  simply  to  this  uranium  X  existing  therein,  the  quan- 
tity of  which  depends  on  a  balance  between  the  rate  at 
which  it  decays  and  the  rate  at  which  the  uranium  manu- 
factures it. 

We  may  attempt  to  illustrate  this  mechanism  by  con- 
structing a  crude  analogy. 

Let  us  suppose  that  we  have  a  full-grown  sweet-pea  vine 
and  that  the  vine  is  the  uranium. 

The  tendrils  of  the  vine  are  the  alpha-rays  from  uranium. 

The  flowers  are  uranium  X. 

The  scent  of  the  flowers  are  the  beta-rays  from  ura- 
nium X. 

Let  us  suppose,  moreover,  that  we  leave  the  vine  strictly 
alone.  We  can  easily  see  that  there  will  come  a  time  in 
our  garden  when  the  flowers  of  the  vine  will  decay  as  fast 
as  the  vine  produces  them,  and  that  the  total  number  of 
flowers  on  the  plant  will  depend  upon  a  balance  between 
their  rate  of  growth  and  decay.  Similarly,  there  comes  a 
time  with  the  uranium,  when  the  amount  of  uranium  X  pro- 
duced decays  as  fast  as  the  uranium  produces  it,  and  the 
total  amount  of  uranium  X  in  the  uranium  depends  upon 
a  balance  between  its  rate  of  growth  and  decay.  If  we 
were  working  with  our  flowers  in  the  dark  as  we  are,  met- 
aphorically speaking,  with  our  uranium,  we  might  estimate 
'their  number  by  picking  them  out  by  their  scent;  we  do 
estimate  the  amount  of  uranium  X  formed  by  the  amount 
of  its  beta-rays.  Now,  let  us  suppose  that  some  dewy 
morning  we  snipped  off  every  flower;  in  other  words  sup- 
pose we  extract  the  uranium  X  from  the  uranium.  We 
now  have  the  flowers  with  their  scent  in  one  hand,  and 
the  uranium  X  with  its  beta-rays  in  the  other.  There  re- 
mains the  destitute  vine  with  its  tendrils  and  the  destitute 


MODERN  ALCHEMY.  143 

uranium  v\  ith  its  alpha-rays.  The  flowers  with  their  scent 
decay  in  our  hand;  so  does  the  uranium  X  with  its  beta- 
rays.  But  the  vine  begins  at  once  to  restore  its  flowers 
with  their  scent  and  soon  has  as  many  as  before;  so  does 
the  uranium  soon  restore  its  uranium  X  with  its  beta-rays. 
We  must  not  be  misled  by  our  analogy:  The  plant  produces 
its  flowers  by  growth,  the  uranium  its  uranium  X  ap- 
parently by  decomposition. 

"But"  you  say,  "  do  you  mean  us  to  infer  that  the  ele- 
ment uranium  (the  element,  mind  you)  is  transformed  into 
a  totally  different  body  ?  "  We  may  as  well  face  the  issue 
squarely.  Yes.  We  do.  Furthermore,  we  believe  that  it 
is  changing  at  a  definite  rate  every  second  of  the  day,  day 
in  and  day  out  forever,  or  at  any  rate  so  long  as  any  of 
it  remains.  We  believe  that  we  have  here  a  veritable  trans- 
mutation of  matter  just  as  wonderful  as  would  be  the  trans- 
mutation of  lead  into  gold,  no  more  no  less.  We  believe 
that  the  alchemists  were  right,  that  matter  is  not  only 
transmutable  but  transmuting,  and  that  without  the  aid  of  I 
any  philosopher's  stone,,  diabolic  influences,  or  even  the^f 
modern  appliances  of  a  scientific  laboratory.  Nay,  in  spite 
of  them ;  for,  apparently,  no  human  effort  can  either  aid  or 
hinder  this  process.  It  seems  to  be  the  very  symbol  of  in- 
evitability. 

We  may  now  imagine  ourselves  confronted  by  an  oppo- 
nent in  the  form  of  a  chemist  of  the  old  school,  one  whose 
mind  has  lost  some  of  its  plasticity  so  that  he  does  not 
readily  assimilate  new  ideas,  but  who,  nevertheless  is  true 
to  the  traditions  of  his  class  in  being  thoroughly  "  skyp- 
tical."  We  can  imagine  this  gentleman  saying:  "Pooh. 
How  do  you  know  that  this  uranium  X  is  different  from 
uranium?"  We  can  answer  this  question  fairly  and 
squarely  by  the  statement  that  it  has  different  chemical 


144  THE    XKW    KXOWLKDGE. 

qualities.  Uranium  is  soluble  in  excess  of  ammonium  car- 
bonate while  the  uranium  X  is  not.  In  a  mixture  of  ether 
and  water,  the  uranium  dissolves  in  the  ether  while  the 
uranium  X  dissolves  in  the  water.  There  is  no  better 
criterion  for  a  difference  in  nature  than  a  difference  in 
chemical  property.  "  But  how  do  you  know,"  says  he, 
"  that  the  element  uranium  has  anything  to  do  with  the 
matter?  You  use  the  uranium  in  the  form  of  a  compound. 
It  is  a  property  of  the  compound,  not  of  the  element." 
No,  it  is  not.  The  radio-activity  of  the  compounds  of  ura- 
nium, and  hence  the  amount  of  uranium  X  formed,  de- 
pends solely  upoh  the  per  cent,  of  uranium  which  the  com- 
pounds contain;  and  it  is  a  matter  of  indifference  whether 
it  is  in  the  form  of  nitrate,  oxide  or  what  not.  Not  only 
so,  but  the  free  element  itself  is  radio-active  and  on  being 
dissolved  will  give  rise  to  uranium  X.  There  is  no  escape 
from  the  fact  that  the  phenomenon  is  a  function  of  the 
element  uranium  itself.  "Well,"  says  the  old  gentleman, 
testily,  "  you  say  that  the  uranium  X  is  a  transitory  ele- 
ment, (save  the  mark  !),  and  that  it  decays.  Now,  what 
does  it  decay  into  ?  What  becomes  of  the  dead  uranium 
X?" 

This  is  an  awkward  question,  so  far  as  uranium  is  con- 
cerned. We  do  not  know  what  becomes  of  the  uranium 
X  for  the  reason  that  it  decays  into  a  body  which  does 
not  emit  rays,  and  its  radio-activity  is  the  only  menus 
by  which  we  can  measure  it.  The  amount  of  uranium  X 
formed  is  so  small  that  it  would  take  geological  epochs 
of  waiting  to  secure  enough  to  weigh,  much  less  examine 
chemically.  But  if  we  cannot  follow  the  process  farther  in 
the  case  of  uranium,  we  certainly  can  in  that  of  an  anal- 
ogous radio-active  body.  For  just  as  uranium  gives  rise 
to  uranium  X,  so  does  the  element  thorium  give  rise  to 


MODERN    ALCHEMY.  145 

a  similar  body,  thorium  X.  Unlike,  however,  uranium  X, 
the  thorium  X,  on  decaying,  gives  rise  to  a  third  radio- 
active body  which  has  been  called  the  thorium  emanation, 
— an  emanation,  because  its  discoverer  Rutherford  was 
unwilling  to  prejudge  the  question  as  to  whether  it  was  a 
gas.  On  dissolving  the  thorium  compound  in  water  and 
bubbling  air  through  it,  this  emanation  passes  away  with 
the  air  and  floats  about  with  it.  Its  presence  is  obvious 
from  its  ray-emitting  power  which  is  intense.  It  is  certainly 
not  finely  disseminated  thorium  X  because  its  rate  of  de- 
cay is  wholly  different.  It  seems  to  be  a  gas.  We  explain 
this  to  our  opponent  who  lifts  his  bushy  eyebrows  and 
quietly  asks:  "If  this  emanation  is  a  gas,  at  what  tem- 
perature does  it  liquify?"  This  is  a  terrible  question,  for 
if  it  is  a  gas,  or  matter  at  all,  there  must  be  a  temperature 
at  which  it  will  condense  just  as  steam  condenses  to 
water  at  100  degrees  Centigrade;  and  our  instruments 
should  be  able  to  determine  this  condensation  through  its 
ray-emitting  power.  We  want  nothing  better,  though,  than 
this  question.  The  emanation  from  thorium  condenses 
sharply  at  a  temperature  of  120  degrees  below  zero  on  the  |j 
Centigrade  scale  to  a  brilliant  patch  of  phosphorescent  light.  , 

We  proceed  to  inform  our  opponent  that  not  only  has  the 
emanation  a  definite  liquifying  point  but  that  it  obeys  Boyle's 
law  in  that,  in  a  definite  volume  of  air,  its  quantity  is  pro- 
portionate to  the  pressure;  and,  further,  that  from  its  rate 
of  diffusion  through  air,  or  through  a  porous  plug,  its  den- 
sity has  been  determined  by  well-known  methods  as  about 
100  times  that  of  hydrogen  gas.  We  heap  this  up  by  say- 
ing that  we  can  even  tell  the  particular  family  of  the  ele- 
ments to  which  the  emanation  belongs;  for  since  it  is  abso- 
lutely indestructible  and  unchangeable  under  the  most 
drastic  chemical  treatment,  it  is,  evidently,  a  gas  belonging 
10 


146  THE  NEW  KNOWLEDGE. 

to  the  argon  family  of  the  elements  in  the  periodic  law. 
This  dazes  the  old  gentleman  a  little,  but  he  returns  to  the 
attack.  "This  so-called  emanation  is  probably  nothing  but 
dust  hi  the  air  which  has  become  radio-active  through  con- 
tact with  the  thorium.  You  know  that  the  international 
congress  of  chemists  has  decided  that  a  new  element,  to 
have  any  validity,  must  have  a  mapped  spectrum.  I  am 
going  to  ask  you,  then,  for  the  spectrum  of  this  emanation 
which  you  tell  me  is  a  transmuted  element  from  thorium." 
This  request  is  hardly  fair,  for  the  instruments  which  meas- 
ure the  properties  of  these  interesting  bodies,  the  electro- 
scope and  electrometer,  are  hundreds  of  thousands  of  times 
more  refined  than  the  most  delicate  spectroscope. 

Yet  we  are  able  to  satisfy  him;  not,  it  is  true,  with  the 
emanation  from  thorium,  for  its  life  is  too  short.  Half  of  it 
has  died  in  a  minute  from  the  time  of  its  birth,  and  this  is  too 
short  a  tune  for  the  adequate  observation  of  the  infinitesi- 
mally  small  quantity  of  matter  involved. 

But  we  can  easily  satisfy  him  with  a  perfectly  similar 
emanation  from  the  new  element  radium ;  for  the  life  of  the 
radium  emanation  is  longer. 

About  the  first  of  June,  1904,  Sir  William  Ramsay  suc- 
ceeded in  determining  with  certainty  the  position  of  certain 
lines  hi  the  spectrum  of  this  transmuted  element,  the  "  em- 
anation" evolved  from  radium. 

The  spectral  lines  characteristic  of  the  emanation  are 
transient  because  the  element  itself  is  transient,  but  they 
are  definite,  and  different  from  the  lines  belonging  to  the 
spectrum  of  any  other  known  form  of  matter. 

It  is  interesting  to  note  in  this  connection  that  one  of  the 
most  persistent  of  the  lines  observed  is  identical  with  one 
observed  in  a  lightning  flash  by  Pickering.  So  sure  is  Ram- 
say that  the  emanation  from  radium  has  a  definite  though 


MODERN    ALCHEMY.  147 

transient  existence  as  a  true  element,  that  he  proposes  to 
give  it  a  definite  name  as  an  element  so  that  it  may  take 
its  place  with  others  in  the  Table  of  the  Elements.     He   '  > 
has  called  it  exradio,  the  element  evolved  out  of  radium. 

11  There  is  just  one  thing  more,"  says  our  sceptical 
chemist,  "that  I  can  fairly  ask  you  to  do.  These  trans- 
muted elements,  such  as  your  emanation,  are  new.  Evolve 
me,  now,  an  element  that  we  know,  —  and  I  shall  be  an 
alchemist." 

We  shall  do  it.  In  June,  1903,  about  one  year  prior  to 
the  discovery  alluded  to  above,  Sir  William  Ramsay  and 
Mr.  Soddy  discovered  that  this  radium  emanation  decayed 
into,  or  became  transmuted  into,  an  entirely  different  ele-  ,' 
ment  with  which  the  world  of  science  has  been  acquainted 
for  years,  —  namely,  the  element  helium.  By  observing 
through  a  spectroscope  a  spectrum-tube  containing  the  ra- 
dium emanation,  they  were  able  to  observe  the  actual 
birth  of  helium.  At  first,  no  spectrum  lines  characteristic 
of  helium  were  observed;  but  presently  they  appeared, 
faint  at  first  but  ever  increasing  in  brightness  until  they 
became  unmistakable,  and  the  birth  of  helium  was  an  ac- 
complished fact.  Helium  has  been  a  well-known  element 
ever  since  its  discovery  on  the  sun  by  Lockyer  twenty-five 
years  ago,  and  its  subsequent  discovery  on  earth  by  Ram- 
say in  1895.  We  have  discovered  that  it  is  a  transmuta- 
tion product  of  the  element  radium. 

"  Well,"  says  our  chemist,  sceptical  no  longer  and  with 
all  the  humour  of  his  class,  "I  am  like  Kipling's  elephant 
when  the  alligator  had  him  by  the  nose.  '  This  is  tooTfuch 


And  so,  in  truth,  it  is. 

We  have  learned,  then,  without  the  use  of  any  theoreti- 
cal conceptions,  and  as  a  matter  of  simple  fact,  that  cer- 


148  THE   NEW  KNOWLEDGE. 

tain  elements  such  as  uranium,  thorium,  radium,  with  as 
much  right  to  the  title  of  elements  as  any  other,  break 
down  or  become  transmuted  into  certain  other  elements 
also,  with  a  perfect  right  to  the  title.  Certain  of  these 
transmuted  elements  have  but  a  brief  span  of  existence, 
and  are  but  half-way  stages  to  some  final  products  of  de- 
composition. The  following  table  shows  us  the  duration  of 
existence  of  some  of  these  transmuted  elements: 

NAME  OF  TRANSMUTED  ELEMENT.   TIME  TAKEN  FOR  HALF  OF  BODY 

TO  UNDERGO  CHANGE. 

Uranium  X,  22  days. 
Thorium  X,  4  days. 

Thorium  emanation,  1  minute. 

Radium  emanation,  3.7  days. 

Radium  emanation  X,  1st  change,  3  minutes. 

2d  change,  21  minutes. 

3d  change,  28  minutes. 

4th  change,      200  years? 

Final  product. 

We  know  this  elemental  transmutation  only  as  it  is  re- 
vealed  by  radio-activity,  the  power  these  elements  possess 
of  emitting  penetrating  rays.  The  instruments  by  which 
these  changes  are  traced  are  hundreds  of  thousands  of  times 
more  sensitive  than  any  known  mechanism,  but  their  re- 
sults are  definite  and  reliable.  The  amount  of  elemental 
transmutation  taking  place  at  any  one  instant  is  exceed- 
ingly small,  but  it  is  actual.  It  is,  at  this  day,  beyond  the 
power  of  man  to  aid  or  hinder  this  process.  It  seems  in- 
evitable. 

Twentieth  Century  Science  has  this  work  to  do.  To  use  the 
prescient  words  of  Faraday  nearly  a  century  old:  "To  de- 


MODERN    ALCHEMY.  149 

compose  the  metals,  to  reform  them,  and  to  realize  the 
once  absurd  notion  of  transmutation,  are  the  problems 
now  given  to  the  chemist  for  solution." 

The  alchemist  became  the  chemist,  and  the  chemist  has 
become  the  alchemist. 


CHAPTER  II. 
(  ATOMIC  DISINTEGRATION.  ) 


Let  us  for  a  moment  come  to  a  pause  with  knowledge  to 
consider  what  we  have  already  gained  without  regard  to  the 
heights  above. 

First,  we  discovered  in  Part  II,  called,  "  The  Mystery  of 
Matter,"  that  the  atoms  of  the  elements  were  so  curiously 
related  to  one  another  that  any  hope  of  explaining  the  mys- 
tery apparently  inherent  in  them  lay  in  the  finding  of  par- 
ticles smaller  than  themselves  out  of  which  they  could  be 
built  up.  Next,  in  Part  III,  called  "Gaseous  Ions,"  we  dis- 
covered that  such  particles,  a  thousand  times  smaller  than 
the  smallest  atom,  do  actually  exist  in  candle-flames  and 
glowing  metals,  within  the  arc-lamps  of  the  street,  in  the 
neighbourhood  of  dynamos,  in  the  presence  of  X-rays,  or  on 
bubbling  gas  through  water.  Furthermore,  in  Part  IV,  on 
"Radio-activity,"  we  found  these  same  particles  flying  off 
with  inconceivable  velocity  from  bodies  in  their  natural 
normal  condition, — bodies  such  as  uranium,  thorium  and 
radium;  and  finally  we  find  that  the  soil  and  water  of 
the  earth  itself  emits  them  and  that  the  air  we  breathe 
contains  them.  These  little  bodies  are  invariably  as- 
sociated with  matter  and  arise  from  matter — from  any 
form  of  matter  under  special  conditions,  and  from  special 
forms  of  matter  under  any  conditions.  From  whatever 
source  they  arise,  these  corpuscles  are  similar  in  all  respects 
with  the  exception  of  mere  velocity. 
(150) 


ATOMIC  DISINTEGRATION.  151 

Since  the  mass  of  the  corpuscles  is  a  thousand  times 
smaller  than  the  mass  of  any  known  atom,  we  see  that  the 
corpuscle  must  be  a  constituent  of  all  substances, — that  as 
a  matter  of  fact,  the  atoms  of  all  the  elements  must  have 
corpuscles  in  common.  We  are  in  this  way  face  to  face 
with  the  idea  that  the  atoms  of  the  chemical  elements  are 
actually  built  up  of  corpuscles.  Evidence  in  support  of 
this  hypothesis  is  not  wanting.  For  example,  on  page  72 
of  Part  III  of  our  work  will  be  found  the  law  of  absorption 
for  corpuscles,  in  which  it  is  apparent  that  the  resistance 
which  substances  interpose  to  the  passage  of  corpuscles 
through  them,  in  other  words,  their  opaqueness,  depends 
solely  upon  the  density  of  the  substance.  If  one  substance 
is  twice  as  heavy  as  another  it  is  only  half  as  transparent 
to  corpuscles.  The  particular  kind  of  matter  has  nothing 
to  do  with  it.  How  different  substances  act  towards  light 
waves  may  be  seen  in  the  case  of  cork  which  is  just  as 
opaque  as  iron.  It  is  all  easily  explicable  on  the  theory  we 
are  considering.  If  each  atom  of  matter  is  built  up  of 
corpuscles  and  if  these  corpuscles  are  extremely  minute 
compared  with  the  atom  as  a  whole,  it  is  evident  enough 
that  we  must  look  upon  an  atom  as  an  open  structure  in 
which  the  vacant  spaces  are  enormous  compared  with  the 
size  of  the  tiny  corpuscles  scattered  throughout  the  atomic 
system.  We  may,  with  Lodge,  illustrate  the  relation  of  a 
corpuscle  to  the  atom  which  it  inhabits,  thus : 

If  we  imagine  an  ordinary  church  to  be  an  atom  of  hy- 
drogen, the  corpuscles  constituting  it  will  be  represented 
by  about  1000  grains  of  sand  each  the  size  of  a  period  so  . , 
dashing  in  all  directions  inside  or  rotating  with  inconceiv- 
able velocity,  and  filling  the  whole  interior  of  the  church 
with  their  tumultuous  motion.  Such  an  atom  would  be 
penetrable  to  other  corpuscles  in  inverse  proportion  to  the 


152  THE   NEW  KNOWLEDGE. 

number  of  corpuscles  constituting  it,  while  it  would  be 
opaque  to  other  atoms.  In  other  words,  the  absorbing 
power  of  a  substance  must,  therefore,  on  the  basis  of  our 
theory,  be  simply  proportional  to  its  density;  and  as 
we  find  it  so  in  fact,  it  makes  our  theory  just  so  much  the 
stronger.  Reinforced  by  this  independent  fact  we  can  there- 
fore go  forward  with  good  courage. 

In  the  preceding  chapter  we  found  that  the  element 
uranium  became  continuously  transmuted  into  a  totally  dif- 
ferent element,  uranium  X,  and  that  the  same  transmuta- 
tion was  true  of  other  elements.  Any  given  •  mass  of  the 
element  uranium  consists  simply  of  x  or  y  atoms  of  that 
element,  and,  hence,  if  there  is  a  transmutation  into  any  other 
element,  it  must  consist,  simply,  in  the  transmutation  of  the 
atom  of  the  first  into  the  atom  of  the  second.  The  trans- 
mutation is  entirely  atomic.  But  this  leads  us  to  think 
that  the  atom  of  any  given  element  consists  not  only  of 
corpuscles  but  of  systems  of  corpuscles.  Take,  for  example, 
the  case  of  thorium.  The  atom  of  thorium  breaks  down 
into  the  atom  of  thorium  X  with  the  evolution  of  material 
particles  that  we  call  the  alpha-rays.  The  atom  of  thorium 
X,  in  its  turn,  breaks  down  into  the  atom  of  the  thorium 
emanation  with  the  evolution  of  still  more  alpha-ray  par- 
ticles. The  atom  of  the  thorium  emanation  follows  the  ex- 
ample of  its  predecessors  in  breaking  down  into  the  atom  of 
the  thorium  emanation  X  again  with  the  evolution  of  alpha 
particles;  and  the  atom  of  the  thorium  emanation  X  itself 
breaks  down  into  some  atom  of  an  unknown  type  with 
an  evolution  not  only  of  the  material  particles  of  the  alpha- 
rays  but  of  beta-  and  gamma-rays  as  well.  The  original 
thorium  must,  therefore,  be  an  exceedingly  complex  sys- 
tem of  corpuscles, — system  within  system — for  it  has  within 
itself  the  potentiality  of  at  least  five  different  atoms.  This 


ATOMIC   DISINTEGRATION.  153 

leads  us  to  think  that,  as  Rowland  long  ago  said/ ' a  broad- 
way  grand  piano  is  a  very  simple  mechanism  compared 
with,  say,  an  atom  of  iron." 

On  the  basis,  then,  of  the  theory  that  the  atom  of  any 
element  is  a  complex  of  corpuscular  systems  we  should  be 
able  to  account  for  the  following  mysteries  of  matter: 

1.  Prout's  Hypothesis,  4.  Group  Relations  of  the 

pp.  19,  20.  Law,  pp.  30-33. 

2.  Triads  of  Dobereiner,         5.  Series  Relations,  p.  29. 

pp.  21,  22. 

3.  The  Periodic  Law,  6.  Valency,  p.  37. 

pp.  22-25. 

7.  The  Inert  Elements  of 

the  Zero  Group,  pp. 
36-38. 

8.  The      electro-chemical 

properties  of  the  ele- 
ments. 

9.  Radio-activity  and  the 

existence  of  unstable 
atoms. 

We  begin  with  a  corpuscle.  We  know  it  to  be  a  particle 
a  thousand  times  smaller  in  mass  than  the  smallest  atom. 
We  know  it  to  possess  a  high  velocity.  We  know  it  also 
to  be  charged,  invariably,  with  a  definite  charge  of  negative 
electricity.  But  since  a  negative  charge  of  electricity  has 
always  associated  with  it  an  equal  positive  charge,  we 
should  expect  the  negative  charge  on  our  corpuscle  to 
follow  the  pattern  of  all  other  negative  charges  and  to  have 
associated  with  it,  too,  an  equal  charge  of  positive  electric- 
ity. Our  atom,  therefore,  we  assume  to  be  a  sphere  of 
positive  electrification  enclosing  a  number  of  negatively 


154  THE   NEW  KNOWLEDGE. 

electrified  corpuscles,  the  negative  electricity  of  the  cor- 
puscles exactly  balancing  the  positive  electricity  of  the  en- 
closing sphere. 

This  is  all  that  Professor  J.  J.  Thomson  requires  for  his 
immensely  important  work  on  the  theory  of  the  structure 
of  the  atom  in  which  the  consequences  of  this  assumption 
are  mathematically  demonstrated.  He  places  before  him 
the  following  questions  for  solution:  (1)  What  would  be 
the  structure  of  such  an  atom,  i.  e.,  how  would  the  cor- 
puscles arrange  themselves  in  the  sphere;  and,  (2)  what 
properties  would  this  structure  confer  upon  the  atom? 

The  answer  to  the  first  question,  how  the  corpuscles 
would  arrange  themselves  in  the  sphere,  depends  on  the  num- 
ber of  corpuscles  and  their  motion.  If  we  assume  that  the 
corpuscles  are  at  rest  they  will  arrange  themselves  within 
the  sphere  so  that  they  are  in  equilibrium  under  the  attract- 
ive force  of  the  sphere  and  their  own  mutual  repulsions. 

If  there  are  two  corpuscles,  only,  A  and  B,  they  will  be 
in  equilibrium  if  placed  on  opposite  sides  of  the  centre  of 
the  sphere  at  a  distance  equal  to  one-half  the  radius.  (Fig. 
42.)  If  there  are  three  corpuscles,  A,  B  and  C,  they  will  be 
in  equilibrium  if  they  form  an  equilateral  triangle  with  its 
centres  at  the  centre  of  the  sphere  (Fig.  43). 


Fig.  42.  Fig.  43. 

Four  corpuscles  will  arrange  themselves  at  the  corners 
of  a   square.    In   all  these    cases  the    corpuscles   arrange 


ATOMIC   DISINTEGRATION.  155 

themselves  as  though  they  were  on  an  inner  sphere  con- 
centric with  the  outer  one  and  it  is  natural  to  suppose  that 
any  number  of  such  corpuscles  could  be  placed  over  such  a 
sphere  and  balanced  by  the  attraction  of  the  outer  sphere 
and  their  own  mutual  repulsions.  Professor  Thomson  has, 
however,  shown  most  decidedly  by  mathematical  calcula- 
tion that  such  is  not  the  fact. 

As  a  matter  of  fact  he  shows  that  unless  the  number  of 
corpuscles  is  small,  not  more  than  five,  this  arrangement  is 
unstable  and  consequently  could  never  maintain  itself. 
When  the  number  of  corpuscles  exceeds  five  they  break  up 
into  two  groups.  The  group  containing  the  smaller  occupies 
the  surface  of  an  inner  shell  towards  the  centre.  The  others 
are  on  an  outer  shell  concentric  with  the  inner  one ,  the 
sphere  of  positive  electrification  surrounding  and  balancing 
them  all.  As  the  number  of  corpuscles  still  further  in- 
creases there  comes  a  stage  at  which  the  equilibrium  cannot 
be  stable  even  with  two  groups  and  the  corpuscles  divide 
themselves  into  three  groups  on  three  concentric  shells ;  and 
as  the  number  increases  after  that,  more  and  more  groups 
are  necessary  for  equilibrium.  This  has  been  neatly  and 
elegantly  shown  by  Professor  Mayer  in  an  experiment 
with  a  model  atom  in  which  the  forces  producing  equilib- 
rium are  similar  to  those  producing  equilibrium  among  the 
corpuscles  in  the  real  atom  as  we  are  considering  it  to  be 
in  nature. 

In  this  experiment,  a  number  of  tiny  magnetized  steel 
needles  thrust  through  discs  of  cork  are  floated  on  water 
so  that  the  little  negative  poles  are  all  above  the  surface 
of  the  water  while  the  positive  poles  are  beneath.  These 
little  floating  negative  magnetic  poles,  just  like  corpuscles, 
repel  each  other  with  forces  varying  inversely  with  the 
square  of  the  distance.  In  this  way  each  little  negative 


156 


THE   NEW   KNOWLEDGE. 


pole  stands  for  a  corpuscle.  The  attractive  force  of  the 
sphere  of  positive  electrification  is  provided  for  by  a  posi- 
tive magnetic  pole  suspended  at  some  distance  above  the 
surface  of  the  water.  The  forces  acting  on  these  little 
floating  magnets  are  thus  similar  to  the  forces  acting  on  the 
corpuscle  in  an  atom.  They  are  free  to  move,  they  repel 
one  another,  and  they  are  attracted  by  an  exterior  radial 
force.  The  main  difference  between  the  corpuscles  and  the 
magnets  is  that  the  corpuscles  may  move  in  any  direction 
in  space,  while  the  floating  magnets  may  move  only  in  the 
plane  of  the  surface  of  the  water.  The  arrangements  as- 
sumed by  the  floating  magnets  as  the  number  increases 
from  two  up  to  nineteen  are  shown  in  Fig.  44. 


Fig.  44. 

Here  we  see  that  three  magnets  form  an  equilateral 
triangle,  four  a  square,  five  a  pentagon,  but  that  when  the 
number  exceeds  five  one  or  more  of  the  mngnets  seek  the 
centre.  Thus  with  six  magnets  we  have  one  at  the  centre 
and  a  pentagon  of  five  surrounding  it.  With,  sa^,  ten 


ATOMIC    DISlXTKdKATION.  157 

magnets  we  have  a  triangular  group  of  three  within  sur- 
rounded by  a  group  of  seven,  and  this  two-group  system 
lasts  until  there  are  fifteen  magnets  when  it  suddenly 
changes  to  a  system  of  three  groups,  one  at  the  centre  sur- 
rounded by  a  pentagon  of  five  which  in  turn  is  surrounded 
by  a  group  of  nine.  This  three-group  arrangement  lasts 
until  the  number  of  magnets  increases  to  twenty-seven 
when  the  four-group  arrangement  comes  in,  one  at  the  cen- 
tre surrounded  by  five  surrounded  by  nine  surrounded  by 
twelve. 

This  is  the  way  our  little  magnets  arrange  themselves. 
It  is  also  the  way  our  little  corpuscles  would  arrange  them- 
selves in  the  atom  if  these  corpuscles  were  at  rest.  It  is 
offered  here  as  a  clever  experimental  verification  of  mathe- 
matical calculation,  and  serves  to  give  us  confidence  in  the 
results  of  the  mathematical  reasoning  we  are  about  to  con- 
sider. Our  little  magnets  are  at  rest,  but  if  they  were  in  a 
state  of  steady  motion  describing  in  their  successive  rings  cir- 
cular orbits  about  the  centre  of  the  sphere  the  effect  of  the 
motion  would  simply  drive  them  farther  away  from  the  centre 
without  in  many  cases  destroying  the  character  of  the  con- 
figuration. The  corpuscles  of  our  atom  we  deem  to  be  in 
such  motion  and  they  must  revolve  in  their  orbits  either 
in  concentric  rings  or  in  concentric  shells.  Professor 
Thomson  has  not  yet  succeeded  in  overcoming  the  mathe- 
matical difficulties  of  their  distribution  in  shells  but  he  is 
able  to  show  that  the  same  kind  of  properties  would  be 
associated  with  shells  as  with  rings.  On  the  latter  basis, 
which  is  almost  as  good  as  the  former,  he  has  for  a  certain 
number  of  them,  solved  the  problem  of  their  distribution. 
The  following  table  shows  the  way  in  which  the  corpuscles 
group  themselves.  The  numbers  range  downward  at  inter- 
vals of  five. 


158 


THE  NEW  KNOWLEDGE. 


Number  of  corpuscles. 

60 

55 

50 

45 

40 

35 

Number  in  successive 
rings. 

20 
16 
13 
8 
3 

19 
16 
12 

7 
1 

18 
15 
11 
5 
1 

17 
14 
10 
4 

16 

13 
8 
3 

16 
12 
6 
1 

Number  of  corpuscles. 

30 

25 

20 

15 

10 

5 

5 

Number  in  successive 
rings. 

15 
10 
5 

13 
9 
3 

12 

7 
1 

10 
5 

8 
2 

Here  is,  also,  the  entire  series  of  arrangements  for  collec- 
tions of  corpuscles  of  which  the  outer  ring  consists  of  twenty 
corpuscles. 


Number    of     corpuscles. 

59 

60 

61 

62 

63 

20 
17 
13 
10 
3 

64 

65 

66 

67 

Number      in   successive 
rings. 

20 
16 
13 
8 
2 

20 
16 
13 
8 
3 

20 
16 
13 
9 
3 

20 
17 
13 
9 
3 

20 
17 
13 
10 
4 

20 
17 
14 
10 

4 

20 
17 
14 
10 
5 

20 
17 
15 
10 
5 

Fifty-nine  is  the  smallest  number  and  67  is  the  largest 
number  of  corpuscles  in  one  collection  that  can  have  an 
outer  ring  of  twenty. 

Let  us  see,  now,  how  these  corpuscles,  with  the  configura- 
tions which  collections  of  them  must  take  to  satisfy  their 
attractive  and  repulsive  forces,  will  answer  for  the  One 
Thing  which  we  found  so  necessary  in  Part  II,  for  any  hope 
of  explaining  the  mysteries  of  the  atoms.  Will  these  col- 
lections of  corpuscles  make  atoms  with  the  properties  pos- 
sessed by  the  atoms  of  the  chemical  elements  ? 

PROUT'S  HYPOTHESIS. 

The  mass  of  the  atom  must  be  the  sum  of  the  masses  of 
the  corpuscles  it  contains,  so  that  the  atomic  weight  is  a 
measure  of  the  number  of  corpuscles  in  the  atom.  Thus, 


ATOMIC  DISINTEGRATION. 


159 


if  the  atom  of  hydrogen  contains  1,000  corpuscles,  oxygen 
will  contain  16,000,  mercury  200,000,  and  so  on.  These 
numbers  will  be  whole  numbers  and  Prout's  hypothesis 
will  be  true,  not  in  the  sense  that  the  atoms  of  all  the  ele- 
ments are  built  up  of  hydrogen  atoms  but  that  they  are 
built  up  of  primordial  atoms  a  thousand  times  smaller  than 
the  hydrogen  atom. 

TRIADS  OF  DOBEREINER. 

We  have  stated  on  page  21  that  out  of  the  list  of  the 
acorns  of  the  elements  little  groups  of  three  could  be 
chosen  with  strongly  correlated  properties  and  owning  to  a 
pronounced  family  relationship ;  wrhile  connected  with  this 
relationship  was  the  curious  fact  that  the  mean  of  the  atomic 
weights  of  the  first  and  the  third  was  approximately,  but 
not  exactly,  equal  to  the  atomic  weight  of  the  middle  one. 
This  previously  incomprehensible  fact  finds  ready  and  sim- 
ple explanation  on  the  basis  of  our  theory  in  the  way  in 
which  the  corpuscles  arrange  themselves  in  groups  to  form 
the  atoms. 

Similarity  of  arrangement  means  similarity  of  property 
throughout  the  whole  range  of  chemistry.  Consequently, 
if  the  collections  of  corpuscles  in  the  tables  above  consti- 
tuted atoms  we  should  not  only  expect,  but  we  should  be 
very  sure,  that  atoms  containing  similar  rings  wrould  possess 
similar  properties.  If  we  take  collections  containing  similar 
rings  we  find  the  Triads  of  Dobereiner,  thus: 


Number  of  corpuscles. 

30 

15 

5 

Number  in  successive  rings. 

15 
10 
5 

10 
5 

5 

Mean  number  of  the  first  and  third. 
Number  in  the  middle  group. 

17-5 
15 

Kit) 


THE   NEW  KNOWLEDGE. 


If  these  collections  of  corpuscles  constituted  atoms,  the 
mean  of  the  atomic  weights  of  the  first  and  third  would 
be  approximately  the  atomic  weight  of  the  middle  one. 

Let  us  take  another  example: 


Number  of  corpuscles. 

61 

41 

25 

Number  in  successive  rin.n's. 

20 
16 
13 
9 
3 

16 
13 
9 
3 

13 
9 
3 

-Mean  number  of  the  first  and  third. 
Number  in  the  middle  group. 

43 
41 

Again  we  find  the  same  thing  true.  If  the  three  col- 
lections of  corpuscles  constituted  three  atoms  they  would 
possess  similar  properties,  and  the  mean  of  the  atomic 
weights  of  the  first  and  third  would  be  approximately  the 
atomic  weight  of  the  middle  one.  The  two  examples  cited 
are  like  those  of  sulphur,  selenium  and  tellurium,  and  of 
chlorine,  bromine  and  iodine,  page  21,  and  the  curious 
facts  recited  there  find  a  simple  rational  explanation. 


THE   PERIODIC   LAW. 

"The  properties  of  an  element  are  a  periodic  function 
of  its  atomic  weight." 

This  has  been  the  great  mystery  of  matter.  If  we  ar- 
range the  elements  of  matter  in  the  order  of  their  atomic 
weights,  from  lowest  to  highest,  similar  properties  periodi- 
cally recur.  For  example :  With  the  element  lithium  cer- 
tain properties  are  associated.  The  elements  immediately 
following  lithium  in  the  order  of  their  atomic  weights  do 
not  possess  these  properties.  They  appear  again,  however, 
when  we  come  to  sodium,  then  disappear  until  potassium 


ATOMIC   DISINTEGRATION.  161 

is  reached,  again  disappear  only  to  reappear  with  rubidium, 
and  so  on.  An  inspection  of  the  tables  given  above  will 
show  that  aggregations  of  corpuscles  as  they  increase  in 
number  from  say  five  to  seventy,  will  possess  properties 
similar  to  those  discovered  in  the  periodic  law.  If,  for 
example,  certain  properties  are  connected  with  a  group  of 
five  corpuscles,  these  properties  will  appear  again  when  the 
number  increases  to  fifteen,  for  fifteen  corpuscles  consist  of 
that  same  group  of  five  with  ten  others  surrounding  it. 
The  properties  connected  with  these  two  groups  of  five  and 
fifteen  corpuscles  will  then  disappear  until  we  again  come 
to  two  groups  of  five  and  ten  corpuscles  respectively,  with 
still  another  ring  surrounding  it.  Inspection  shows  that 
this  occurs  when  the  corpuscles  number  thirty,  where  we 
have  a  group  of  five,  surrounded  by  a  group  of  ten  sur- 
rounded by  a  group  of  fifteen.  For  a  next  recurrence  of 
these  properties  we  must  now  wait  until  the  corpuscles 
number  forty-seven,  when  we  again  find  the  grouping  five, 
ten,  fifteen,  this  time  surrounded  by  a  group  of  seventeen  cor- 
puscles. The  arrangement  then  disappears  to  recur  again 
with  sixty-seven  corpuscles  in  the  grouping  five,  ten,  fifteen, 
seventeen,  twenty.  This  periodic  rebuilding  or  recurrence 
of  the  same  groups  as  the  number  of  corpuscles  increases 
is  wonderfully  analogous  to  the  periodic  appearance  and 
disappearance  of  certain  properties  of  the  elements  as  the 
atomic  weight  rises;  and  if  the  atomic  weight  is  measured 
by  the  number  of  corpuscles  the  atom  contains,  and  the 
properties  of  the  atom  are  dependent  upon  the  arrange- 
ment and  grouping  of  the  corpuscles  within  the  atom,  it  is 
obvious  that  we  have,  to  a  reasonable  degree,  solved  the 
problem  of  the  periodic  law.  It  means,  simply,  the  periodic  i 
recurrence  of  certain  groups  of  corpuscles  as  the  number  u~* 
of  corpuscles  constituting  the  atom  increases.  The  peri-  ' 
11 


162 


THE   NEW  KNOWLEDGE. 


odic   recurrence  of  properties  turns  out  to  be,  in  fact,  a 
necessity  if  the  atoms  are  built  up  of  corpuscles. 

GROUP   RELATIONS   OF   THE   LAW. 

The  fact  that  atoms  built  up  of  corpuscles  necessarily 
result  in  a  periodic  law  has,  as  a  further  necessary  conse- 
quence, the  existence  of  natural  families  among  the  ele- 
ments. If  the  reader  will  re-inspect  the  table  of  the  cor- 
puscular groupings  he  will  find,  for  example,  that  the 
group  of  60  corpuscles  consists  of  the  same  rings  of 
corpuscles  as  the  group  of  40,  with  an  additional  ring 
of  20  corpuscles  around  it,  while  the  group  of  40  consists 
of  the  same  rings  as  the  group  of  24,  with  an  additional 
ring  outside,  while  24  is  the  group  11  with  an  additional 
ring,  11  being  the  group  3  with  an  additional  ring,  thus: 


Number  of  corpuscles. 

60 

40 

24 

11 

3 

Number  of  corpuscles  in  successive 
rings. 

(A    family    of    five    corpuscular 
groupings.) 

20 
16 
13 
8 
3 

16 
13 
8 
3 

13 

8 
3 

8 
3 

3 

We  see,  in  this  way,  that  we  can  divide  the  various 
groups  of  corpuscles  into  families  such  that  each  member 
of  the  family  is  derived  from  the  preceding  member,  (the 
member  just  above  it  in  the  vertical  columns  of  the  table 
of  the  periodic  law),  by  adding  to  it  another  ring  of  cor- 
puscles. 

We  should  expect  atoms  formed  in  this  way  of  related 
groups  of  corpuscles  to  possess  resembling  properties;  and 
since  in  the  elements  themselves  we  find  such  groups,  it 
would  be  strange  if  their  actual  existence  and  the  necessity 
for  their  existence  on  the  basis  of  our  theory  had  no  sig- 
nificance or  relation.  Professor  Thomson  has  recently 


ATOMIC    DISINTEGRATION.  163 

shown,  on  mathematical  grounds,  that  such  related  groups 
of  corpuscles  would  of  necessity  possess  related  spectra 
such  as  have  lately  been  discovered  among  the  elements  of 
certain  groups  in  the  table  of  the  periodic  lawr.  This  is  a 
strong  confirmation  of  our  theory. 

SERIES  RELATIONS. 

But  the  atoms  of  matter  as  they  appear  in  the  table  of 
the  periodic  law  are  related  not  only  in  groups  but  in 
series,  (page  29).  A  series  is  a  horizontal  row  of  ele- 
ments in  the  table  as  a  group  is  a  vertical  one.  The 
gradual  change  in  the  properties  of  the  elements  which 
takes  place  as  we  travel  along  one  of  these  horizontal  rows 
is  also  illustrated  in  the  properties  possessed  by  these  groups 
of  corpuscles.  To  demonstrate  this,  consider,  for  example, 
the  series  of  arrangements  of  the  corpuscles  given  on  page 
158,  in  all  of  which  the  outer  ring  contains  20  corpuscles. 
An  outer  ring  containing  20  first  occurs  in  a  group  of  59 
corpuscles.  Professor  Thomson  shows  that  in  this  case 
of  59  corpuscles  the  number  of  corpuscles  inside  is  only 
just  sufficient  to  make  the  outer  ring  of  20  stable;  this 
ring  will,  therefore,  be  on  the  verge  of  instability  and  when 
its  corpuscles  are  displaced,  the  forces  urging  them  back 
again  will  be  small. 

For  this  reason,  when  the  ring  is  subjected  to  an  exter- 
nal disturbance,  one  or  more  corpuscles  may  easily  be  de- 
tached from  it.  We  must  remember,  though,  that  in  these 
collections  of  corpuscles,  the  negative  electricity  of  the 
collection  is  exactly  balanced  by  the  sphere  of  positive 
electricity  surrounding  it  and  enclosing  it;  and,  hence,  if 
one  negative  corpuscle  is  lost  the  whole  arrangement  will 
assume  a  positive  charge.  Such  an  atom  would  behave 
like  the  atom  of  a  strongly  electro-positive  or  basic  element. 


164  THE   NEW   KNOWLEDGE. 

With  the  next  group,  60  corpuscles,  the  outer  ring  is  more 
stable  because  there  is  an  additional  corpuscle  inside  it. 
While,  therefore,  it  may  lose  corpuscles  it  will  not  do  so  so 
readily  as  the  group  of  59.  Hence,  it  will  not  so  easily  as- 
sume the  positive  charge  of  electricity,  and  hence,  again,  it 
will  not  be  so  electro-positive  an  element  as  the  group  of  59. 

61  corpuscles  will  be  still  less  electro-positive  than  60,  and 

62  less  than  61.    The  addition  of  each  successive  corpuscle 
inside  will  make  it  more  difficult  to  detach  corpuscles  from 
the  outer  ring  of  20  and  will,  therefore,  make  the  atom  less 
electro-positive.    Not  only  so,  but  when  the  total  number 
of  corpuscles  increases  to,  say,  63  the  possibility  of  losing 
corpuscles  from  the  outer  ring  vanishes  and,  instead,  another 
possibility  creeps  in.    When  the  stability  of  the  atom  be- 
comes extreme  one  or  more  corpuscles  of  the  outer  ring  may 
actually  lie  on  the  surface  of  the  atom  without  breaking  the 
ring.     In  this  case  the  atom  would  receive  a  charge  of  neg- 
ative electricity  and  would  behave  like   the  atom  of  an 
electro-negative  element.    This  increase  in  the  stability  of 
the  ring,  and  consequently  in  the  electro-negative  character 
of  its  atom  would  go  on  growing  until  we  had  as  many  as 
67  corpuscles  where  the  stability  of  the  ring  would  be  at  a 
maximum.    Sixty-seven  corpuscles  would  result  in  a  strongly 
electro-negative  element  like  chlorine. 

A  great  change  however  in  the  properties  of  the  atom 
takes  place  in  the  next  group  of  68  corpuscles  for  now  the 
number  of  corpuscles  in  the  outer  ring  increases  to  21,  these 
21  corpuscles  are  however  only  just  stable,  and  would  like 
the  outer  ring  of  20  in  the  arrangement  of  59  corpuscles, 
readily  lose  a  corpuscle  and  so  make  the  atom  strongly 
electro-positive.  An  atom  of  68  corpuscles  would  therefore 
strongly  resemble  the  atom  of  59,  one  of  69  would  resemble 
that  of  60,  70  that  of  61  and  so  on.  The  properties  of  the 


ATOMIC   DISINTEGRATION.  165 

groups  of  59  and  67  corpuscles  are  exceedingly  interesting. 
We  have  said  that  59  corpuscles  are  on  the  very  verge  of 
instability  and  would,  hence,  readily  lose  a  corpuscle  and 
thereby  acquire  a  positive  charge.  But  they  would  not  re- 
tain this  charge.  For  when  the  group  had  lost  a  corpuscle 
58  corpuscles  would  remain.  But  58  corpuscles  constitute 
the  last  group  which  has  an  outer  ring  of  19.  This  ring 
is  exceedingly  stable  just  as  the  ring  of  67  corpuscles  is 
stable  so  that  no  more  corpuscles  could  escape  from  it, 
while  the  positive  charge  on  it  due  to  the  escape  of  the  59th 
corpuscle  would  attract  the  surrounding  corpuscles  and  one 
would  immediately  dart  to  it  and  become  attached  to  it, 
when  it  would  become  once  more  59  only  to  reundergo  the 
same  change  over  and  over  and  over  again.  An  atom  so 
constituted  would  be  neither  electro-positive  nor  electro- 
negative but  one  incapable  of  receiving  any  charge  of  elec- 
tricity whatever.  The  group  containing  60  corpuscles 
would  be  the  most  electro-positive  of  the  series.  It  could 
lose  only  one  corpuscle,  that  is,  acquire  a  charge  of  only 
one  unit  of  positive  electricity,  for  if  it  lost  two  we  should 
again  have  58  corpuscles  which  would  have  double  the  pos- 
itive charge  and  double  the  readiness  to  catch  corpuscles 
which  we  found  in  the  group  of  59.  Thus  the  group  of 
60  corpuscles  would  get  charged  with  one,  and  one  only,  \ 
unit  of  positive  electricity.  It  would  thus  behave  like  the  \ 
atom  of  a  monovalent  electro-positive  element  like  sodium. 
The  group  containing  61  corpuscles  would  not  be  so  ready 
to  lose  its  corpuscles  as  the  group  of  60,  but  on  the  other 
hand  it  could  afford  to  lose  two  for  it  is  not  until  it  has  lost 
three  that  its  corpuscles  become  reduced  to  58  when,  as  we 
have  seen,  it  begins  to  acquire  fresh  corpuscles.  It  would 
thus  act  like  the  divalent  positive  element  magnesium. 
Similarly  the  group  of  62  though  less  willing  to  lose  its  cor- 


166  THE    XEAV   KNOWLEDGE. 

puscles  than  61  could  on  the  other  hand  afford  to  lose  three 
before  beginning  to  seize  more.  It  would  thus  act  like,  let 
us  say,  the  element  aluminum. 

Turning  now  to  the  other  interesting  group,  67  corpuscles, 
at  the  end  of  the  series,  we  find  that  its  ring  of  20  corpuscles 
is  more  stable  than  any  of  the  others,  but  if  the  system 
acquires  another  corpuscle  the  68  corpuscles  would  arrange 
themselves  with  a  ring  of  21  on  the  outside.  This  group- 
ing as  we  have  seen  is  on  the  very  verge  of  instability  and 
would  readily  lose  its  corpuscle  and  pass  back  again  into 
its  old  configuration.  Consequently,  the  group  of  67  cor- 
puscles like  the  group  of  59  is  incapable  of  receiving  a  charge 
at  all.  The  group  of  66  would  be  the  most  electro-negative 
of  the  series  but  it  could  alford  to  retain  only  one  unit  of 
negative  electricity  for  if  it  acquired  two  there  would  be  68 
a  system  which  we  have  seen  to  be  unstable.  It  would 
thus  act  like  a  very  strongly  electro-negative  element  like 
chlorine. 

The  group  of  65  though  less  ready  than  66  to  retain 
corpuscles  could,  nevertheless,  retain  two  and  hence  would 
act  like  a  divalent  negative  element  like  sulphur.  Similarly 
the  group  of  64  would  act  like  the  atom  of  a  trivalent 
element  after  the  style  of  phosphorus. 

Thus  taking  those  groups  of  corpuscles  which  contain  20 
corpuscles  in  their  outer  rings  and  numbering  from  59  to 
67  respectively  we  are  able  to  show  that  they  would  neces- 
sarily behave  in  their  general  properties  like  a  horizontal 
series  of  elements  in  the  periodic  law. 

VALENCY. 

We  are  now  able,  to  a  reasonable  extent,  to  explain  val- 
ency, page  37.  Valency  we  have  always  defined  in  chemistry 


ATOMIC   DISINTEGRATION.  167 

as  the  saturation  capacity  of  an  atom,  the  power  possessed 
by  an  atom  to  unite  with  others,  in  other  words,  its 
"grabbing  power."  We  have  never  known  the  meaning  of 
it.  We  can  see  now  that  it  is  electrical  in  its  origin.  A 
univalent  positive  atom  is  one  which,  under  the  circum- 
stances of  chemical  action,  attains  stability  by  losing  one, 
and  only  one,  corpuscle.  A  univalent  negative  atom,  like 
chlorine,  is  one  that  will  acquire  one,  and  only  one,  corpus- 
cle. A  divalent  positive  atom  is  one  which  will  lose  two 
corpuscles  and  no  more,  and  so  on.  The  valency  of  the 
atom  is  thus  simply  a  question  of  the  number  of  corpuscles 
that  can  escape  from  or  be  received  by  the  corpuscular 
grouping  which  constitutes  any  one  kind  of  atom.  Thus 
the  valency  as  well  as  the  other  properties  of  elements  such 
as  neon,  sodium,  magnesium,  aluminum,  silicon,  phosphorus 
sulphur,  chlorine  and  argon  of  the  2d  series  of  the  peri- 
odic law  are  the  properties  and  valencies  of  groups  of  59, 
60,  61 ,  62,  63,  64,  65,  66  and  67,  corpuscles  respectively. 

CHEMICAL  ACTION. 

Chemical  action  can  also  be  explained  as  electrical  and 
corpuscular  in  its  nature.  Suppose  that  we  have  a  num- 
ber of  sodium  atoms  which  are  capable  of  losing  one  cor- 
puscle each  mixed  with  the  same  number  of  chlorine  atoms 
which  are  capable,  on  this  theory,  of  acquiring  one  corpus- 
cle each.  Then  the  corpuscles  which  escape  from  the  sodium 
atoms  will  find  a  home  on  the  chlorine  atoms  which  are  well 
able  to  retain  them. 

The  result  of  this  is  that  all  the  sodium  atoms  will  ac- 
quire their  unit  positive  charge  and  all  the  chlorine  atoms 
their  unit  negative  charge.  The  positive  atoms  of  sodium 
will  then  attract  the  negative  atoms  of  chlorine,  electrically, 
and  we  shall  obtain  the  compound  sodium  chloride  or  com- 


168  THE   NEW  KNOWLEDGE. 

mon  salt.     Other  chemical  reactions  can  be  explained  in 
the  same  way.    Chemical  affinity  is  electrical  affinity. 

THE  INERT  ELEMENTS  OF  THE  ZERO  GROUP. 

The  rare  gases  of  the  atmosphere,  such  as  helium,  neon 
and  argon,  which  were  a  few  years  ago  discovered  by  the 
masterly  researches  of  Rayleigh,  Ramsay  and  Travers,  and 
which  are  now  associated  together  in  the  zero  group  of 
the  periodic  law,  bear  out  in  a  most  interesting  and  re- 
markable way  the  corpuscular  theory  we  are  considering. 
These  gases  are  alike  in  this,  that  they  have  no  combining 
power,  or  valency,  whatever.  They  combine  chemically  with 
no  known  element.  In  our  study  of  corpuscular  groupings 
we  found  that  a  group  of  59  corpuscles  and  a  group  of  67 
corpuscles  were  in  precisely  this  position  that  they  were 
hopelessly  unable  to  retain  any  electrical  charge  whatever, 
that  is,  unable,  permanently,  either  to  lose  or  to  acquire  a 
corpuscle.  If,  as  we  have  said,  chemical  action  means 
simply  the  power  either  to  lose  or  to  acquire  corpuscles,  it 
is  obvious  that  atoms  built  up  of  such  corpuscular  groups 
would  be  quite  unable  to  enter  into  chemical  combination. 
They  would,  therefore,  be  like  helium  and  neon.  Not  only 
so,  but  these  groups  occur  at  the  proper  intervals.  They 
occur  with  seven  groups  in  between,  just  as  helium  and 
neon  occur  with  seven  atoms  in  between. 

It  is  very  evident  then  that  if,  as  we  said  in  Part  II,  the 
rare  gases  of  the  atmosphere  have  found  a  home  in  the 
periodic  law,  they  have  also  found  a  home  in  the  corpus- 
cular theory  which  explains  that  law. 

RADIO-ACTIVITY  AND  THE  EXISTENCE  OF  UNSTABLE  ATOMS. 

But  the  corpuscular  theory  of  the  atom  must  explain 
the  transmutation  of  matter  as  it  is  seen  to  take  place  in 


ATOMIC   DISINTEGRATION.  169 

the  radio-active  elements.  It  must  also  explain  radio-activ- 
ity in  general.  Any  failing  in  this  respect  would  be  fatal  to 
its  acceptance.  It  was  stated,  page  152,  that  an  atom  of  one 
of  the  radio-active  elements  should  consist  not  only  of  cor- 
puscles but  of  systems  of  corpuscles.  This  finds  its  expla- 
nation in  the  systems  of  rings  into  which  we  have  shown  the 
corpuscles  would  necessarily  arrange  themselves.  In  addi- 
tion to  this,  however,  Professor  Thomson  has  proved  that 
these  rings  of  corpuscles  need  not  be  concentric.  A  tri- 
angular ring  of  three  corpuscles,  for  example,  may  exist 
anywhere  in  the  atomic  sphere  surrounded  by  positive  elec- 
tricity, and  yet  retain  its  integrity  and  act  like  one  corpus- 
cle. We  see  that  the  evident  complexity  of  an  atom  of 
radium  need  not  worry  the  theory,  for  the  vast  number  of  cor- 
puscles it  would  contain,  about  225,000  on  the  basis  of  its 
atomic  weight,  would  of  course  be  exceedingly  complex. 
The  explanation  of  transmutation  and  radio-activity,  how- 
ever, lies  in  the  energy  of  the  corpuscles,  and  in  the  fact 
that  the  configurations  adopted  by  the  corpuscles  depend  in 
certain  cases  on  the  energy  they  contain.  This  is  shown  in 
the  arrangements  adopted  by  the  little  magnets,  Fig.  44, 
where  we  find  that  five  corpuscles  may  arrange  themselves 
either  in  a  pentagon  or  in  a  square  with  one  corpuscle  in 
the  centre.  Professor  Thomson  has  demonstrated  mathe- 
matically that  a  group  of  four  corpuscles,  for  example,  rotat- 
ing with  an  angular  velocity  greater  than  a  certain  critical 
value  will  arrange  themselves  at  the  corners  of  a  square,  but 
that  if  the  velocity  falls  below  this  value  they  will  suddenly 
arrange  themselves  this  time  at  the  corners  of  a  tetrahe- 
dron. Let  us  suppose  now  that  we  have  an  atom  contain- 
ing a  system  of  corpuscles  of  this  kind.  Suppose  that  the 
corpuscles  are  rotating  with  an  angular  velocity  far  beyond 
the  critical  velocity.  The  configuration  is  stable  enough. 


170  THE   NEW   KNOWLEDGE. 

But  owing  to  the  radiation  of  energy,  the  velocity  is  going 
to  diminish,  slowly,  very  slowly,  but  certainly.  There  will 
come  a  time,  then,  and  a  definite  time,  when  this  critical 
velocity  will  be  reached  and  then,  presto !  there  will  be  sud- 
den convulsion,  or  explosion,  and  the  rearrangement  is  ac- 
complished. 

The  potential  energy  is  decreased,  the  kinetic  energy  is 
increased. 

This  arrangement  must  mean  the  evolution  of  a  large 
amount  of  kinetic  energy,  and  it  has  been  shown  that  it 
might  easily  be  sufficient  to  carry  the  system  out  of  the 
atom  altogether  and  we  should  have,  as  in  the  case  of  ra- 
dium, a  part  of  the  atom  shot  off  with  high  velocity. 

It  is  very  like  the  case  of  a  spinning  top.  The  top  is 
stable  in  a  vertical  position  if  the  kinetic  energy  due  to  its 
rotation  exceeds  a  certain  value.  When,  however,  the  veloc- 
ity diminishes  to  this  critical  point,  the  crash  comes  and 
away  goes  the  top,  helter-skelter. 

This  all  agrees  with  the  facts  of  radio-activity.  The 
radio-activity  of  radium,  for  example,  is  thus  an  atomic 
cataclysm.  When  the  point  of  instability  is  reached  the 
explosion  occurs  with  the  projection  of  two  kinds  of  particles 
which  are  sub-atoms  inside  the  group  but  free  atoms  outside. 

One  of  these  is  the  alpha  particle  consisting  of  two  or 
three  thousand  corpuscles  and  the  other  is  the  atom  of  the 
emanation  which  contains  probably  about  150,000.  The 
atom  of  the  emanation  is  of  the  same  type  as  the  atom  of 
radium.  Its  configuration  for  steady  motion  depends  on 
its  kinetic  energy.  Consequently  the  process  is  repeated 
for  the  emanation,  but  in  a  very  much  shorter  time,  and  we 
again  have  the  evolution  of  alpha  particles,  which  seems  as 
a  matter  of  fact  to  be  the  atom  of  helium,  together  with 
the  formation  of  another  atomic  system  called  emanation  X. 


ATOMIC   DISINTEGRATION.  171 

This,  too,  breaks  down  but  this  time  with  a  perfect  con- 
flagration of  decomposition  in  which  the  alpha  particles,  the 
stray  corpuscles,  or  beta-rays,  and  the  gamma-rays  all  ap- 
pear together. 

We  may,  therefore,  define  a  radio-active  substance  as  one 
whose  atom  consists  of  a  complex  group  of  corpuscles  the 
configuration  of  which  depends  for  its  maintenance  upon  a 
certain  velocity  of  movement  of  the  corpuscles  comprising 
it  and  beneath  which  velocity  the  corpuscles  rearrange 
themselves  with  the  evolution  of  an  amount  of  energy  which 
breaks  down  the  atom. 

Our  theory  of  an  atom  is  that  it  is  a  sphere  of  positive 
electrification  enclosing  a  number  of  negatively  electrified 
corpuscles  the  negative  electricity  of  the  corpuscles  exactly 
balancing  the  positive  electricity  of  the  enclosing  sphere. 
( )n  this  theory  we  have  been  able  to  explain  all  the  mysteries 
of  matter,  which  it  has  been  the  function  of  preceding  chap- 
ters to  describe,  in  terms  of  what  we  already  know. 

We  have  been  able  to  show,  also,  that  these  mysteries  of 
matter  inevitably  result  from  the  acceptance  of  the  theory. 


CHAPTER  III. 
INTERATOMIC  ENERGY. 

March,  1903,  was  an  historic  date  for  chemistry.  It  is, 
also,  as  we  shall  show,  a  date  to  which,  in  all  probability, 
the  men  of  the  future  will  often  refer  as  the  veritable  be- 
ginning of  the  larger  powers  and  energies  that  they  will 
control.  It  was  in  March,  1903,  that  Curie  and  Laborde 
announced  the  heat-emitting  power  of  radium.  The  fact 
was  simple  of  demonstration  and  unquestionable.  They 
discovered  that  a  radium  compound  continuously  emits 
heat  without  combustion  or  change  in  its  molecular  struc- 
ture. The  heat  emitted  is  sufficient  to  maintain  the  tem- 
perature of  the  radium  1.5  degrees  Centigrade,  or  about 
2.7  degrees  Fahrenheit,  above  that  of  its  surroundings. 
It  is  all  just  as  surprising  as  though  Curie  had  discovered 
a  red-hot  stove  which  required  no  fuel  to  maintain  it  in 
heat.  Stated  in  another  way,  one  gram  of  radium  com- 
pound emits  100  gram-calories  of  heat  per  hour.  This 
means  that  every  hour  it  emits  enough  heat  to  raise  its  own 
weight  of  water  from  the  freezing-point  to  the  boiling- 
point. 

It  is  enough  to  raise  its  own  weight  of  water  one  degree 
in  36  seconds.  In  about  40  hours  sufficient  heat  has  been 
evolved  from  the  gram  of  radium  to  decompose  its  own 
weight  of  water  completely  into  its  constituents,  hydrogen 
and  oxygen.  After  the  lapse  of  10,000  hours  (13.5  months) 
there  has  been  enough  heat  emitted  to  raise  the  temper- 
ature of  a  million  times  its  weight  of  water  one  degree. 
(172) 


1XTERATOMIC  ENERGY.  173 

It  is  necessary  to  analyze  out  this  remarkable  fact.  We 
know  that  the  radio-activity  of  a  mass  of  radium  compound 
is  complex  and  consists  of  the  united  activities  of  the  ra- 
dium itself  and  its  disintegration  products,  the  emanation, 
the  emanation  X  and  the  two  or  three  active  bodies  into 
which  the  emanation  X  successively  breaks  down.  It  has 
been  determined  that  the  heat  emission  is  due  almost  en- 
tirely to  the  alpha-rays,  the  positively  electrified  particles 
of  atomic  dimensions.  In  a  mass  of  radium  nearly  all  the 
alpha-rays  emitted  from  it  are  absorbed  in  the  radium  it- 
self. The  radium  is  thus  subjected  to  an  intense  bombard- 
ment by  the  alpha  particles  projected  from  its  own  mass. 
It  is  little  wonder,  under  the  circumstances,  that  the  ra- 
dium is  heated.  The  energy  of  the  alpha  particles  is  im- 
mense. These  particles,  small  as  they  are,  are  2,000  times 
the  mass  of  a  corpuscle  and  travel  with  a  velocity  40,000 
times  that  of  the  swiftest  rifle  bullet.  If  an  alpha  par- 
ticle were  the  size  of  a  cannon  ball  the  heat  generated  by 
its  impact  on  the  target  would  be  many  times  more  than 
sufficient  not  only  to  melt  it  but  to  dissipate  it  into  vapour. 
But  the  alpha  particles  are  projected  not  only  from  radium 
itself  but  from  all  its  disintegration  products;  and  we  dis- 
cover that  the  heat  emission  is  distributed  thus : 

Radium  freed  from  active  products.     .     .  25  per-cent. 

Emanation  and  successive  active  products.  75  "  " 
Seventy-five  calories,  then,  of  the  heat  emitted  from  a  gram 
of  radium  are  due  to  the  emanation  stored  therein.  But 
the  volume  of  the  emanation  is  infinitesimally  small.  From 
one  gram  of  radium  compound  the  volume  of  the  emana- 
tion evolved  would  not  amount  to  more  than  1.3  of  a  cubic 
millimetre.  This  needle  point  of  gas  evolves  enough  heat 
per  hour  to  raise  the  temperature  of  75  grams  of  water  one 
degree.  If  it  were  possible  to  obtain  one  cubic  centimetre 


174  THE   NEW  KNOWLEDGE. 

(a  thimbleful)  of  this  emanation  in  the  form  of  a  gas  we 
should  find  that  it  possessed  the  power  of  emitting,  alto- 
gether, over  seven  million  calories  of  heat !  This  is  more 
than  sufficient  to  raise  15,000  pounds  of  water  one  degree, 
and  all  this  heat  from  a  thimbleful  of  an  invisible  gas ! 
The  important  phase  of  this  statement  is  that  it  is  alto- 
gether outside  of  any  hypothesis  or  theory.  It  is  a  simple 
straightforward  fact.  Now,  the  heat  evolved  by  explod- 
ing the  same  volume  of  hydrogen  and  oxygen  mixed  in  the 
proportions  required  to  form  water  is  about  two  calories. 
We  find  then  that  the  heat  evolved  by  the  radium  emanation 
is  over  three  million  five  hundred  thousand  times  greater  than 
that  let  loose  by  any  known  chemical  reaction.  This  seems  to 
be  an  unanswerable  reply  to  those  who  would  ascribe  the 
energy  of  radio-activity  to  ordinary  chemical  action  or,  on 
the  other  hand,  to  those  who  would  ascribe  it,  instead,  to 
an  external  source  which,  hypothetically,  the  radium  atom 
alone  has  the  power  to  respond  to.  With  the  passing 
away  of  these  interpretations  we  are  locked  up  with  the 
only  other  conclusion  possible, — that  the  radio-activity  is 
due  to  an  enormous  store  of  energy  within  the  radium  atom 
itself.  The  energy  of  radio-activity  is  interatomic. 

The  amount  of  heat  generated  by  radium  gives  us  some 
additional  general  information.  In  any  mass  of  radium 
not  all  its  atoms  are  disintegrating  at  the  same  time.  In 
:  the  foregoing  chapter  we  were  led  to  understand  that  they 
would  go  to  pieces  only  as  they  became  unstable,  and  that 
this  instability  was  a  mere  chance  for  an  individual  atom, 
though  a  constant  for  the  average  one.  It  is  interesting 
to  know  how  many  atoms  of  radium  disintegrate  per 
second.  If  we  ascribe  the  heat  emission  to  the  alpha  par- 
ticles we  are  let  into  the  secret.  In  the  case  of  radium 
there  arc  at  least  four  stages  in  the  disintegration,  each 


INTERATOMIC   ENERGY.  175 

one  of  which  is  accompanied  by  the  expulsion  of  an  alpha 
particle.  Therefore,  four  is  the  very  least  number  pro- 
duced from  any  one  atom  of  disintegrating  radium.  On 
this  basis,  calculation  leads  to  the  conclusion  that  in  every 
mass  of  radium,  however  great  or  however  small,  not  more 
than  thirteen  trillionths  of  it  is  undergoing  change  per  sec- 
ond, and  all  its  radiated  energy  is  due  to  this  infinitesimal 
portion  of  it.  Knowing  the  amount  of  radium  undergoing 
change  per  second,  it  is  possible  to  deduce  the  average 
life  of  the  radium  atom.  This  life  is  about  2,450  years  as 
a  minimum  estimate.  It  is  obvious  from  this  that  the  radium 
at  present  existent  in  the  world  has  not  always  been  with 
us.  It  has  come  into  existence  since  the  formation  of  the 
world.  It  is  also  obvious  that  in  the  course  of  a  few  thou- 
sand years  all  the  radium  at  present  existing  will  be  re- 
duced to  practically  nothing.  What  we  have  in  the  world 
to-day  has  come  to  be,  and  will  cease  to  be,  within  the 
time  of  man.  We  may  ask,  then,  is  it  an  unprecedented 
substance,  the  phenomenon  of  a  day  in  all  time? 

Not  likely.  Certain  indications  point  to  the  conclusion 
that  radium  is  itself  a  disintegration  product  from  the 
heavier,  and  more  slowly  changing,  radio-active  element  J 
uranium.  It  turns  out  that  the  relative  proportion  of 
radium  to  uranium  in  the  different  radio-active  minerals 
from  which  radium  is  extracted  is  a  constant  quantity. 
This  is  just  as  it  should  be  if  uranium  were  the  parent  of 
radium.  But  there  is  contrary  evidence.  If  uranium  is 
the  parent  of  radium,  the  actual  genesis  of  the  radium 
ought  to  be  capable  of  detection.  Soddy  has  tested  this 
point  by  carefully  extracting  all  the  radium  from  a  mass  of 
uranium  nitrate  and  testing  the  uranium  for  the  growth  of 
radium  at  frequent  intervals  throughout  a  year.  He  has 
been  able  to  show  that  if  radium  is  generated  its  quantity 


176  THE    NEW   KNOWLEDGE. 

is  100,000  times  less  than  it,  theoretically,  should  be. 
The  source  of  radium  is,  therefore,  still  an  open  question, 
though  we  may  be  fairly  sure  that  its  generation  is  con- 
stant from  some  source  or  other,  and  that  its  decay  will  be 
balanced  by  a  constant  fresh  supply. 

The  amount  of  energy  locked  up  in  a  gram  of  innocent 
looking  radium  bromide  and  appearing  as  heat  on  the  dis- 
integration of  the  whole  gram,  calculates  out  to  about  one 
billion  calories, — a  prodigious  quantity  of  energy.  This 
energy  is  not  the  total  amount  contained  in  the  radium. 
It  is  only  that  portion  which  becomes  manifest  on  the  de- 
composition of  the  radium  into  its  disintegration  products. 
If  the  gram  of  radium  could  be  wholly  dissociated  into 
corpuscles,  the  energy  let  loose  would  greatly  exceed  the 
above  amount. 

But  radio-active  substances  in  their  normal  character  as 
chemical  elements  are  in  no  way  different  from  the  inactive 
elements.  Radium  is  like  barium  and  strontium;  uranium 
is  like  tungsten  and  molybdenum ;  polonium  is  like  bismuth  ; 
and  thorium  is  like  titanium.  If  it  were  not  for  their 
bizarre  property  of  radio-activity  they  would  be  in  no 
sense  remarkable.  Hence,  it  is  impossible  for  us  to  come 
to  any  other  conclusion  than  that  there  is  locked  up  in 
all  the  so-called  "elements"  of  matter  an  enormous 
store  of  energy  which,  except  in  those  elements  of  heaviest 
atomic  weight  like  radium  and  thorium,  remains  latent  and 
unknown.  Professor  Thomson  as  the  result  of  his  calcula- 
tions, concludes  that  a  gram  of  hydrogen  has  within  it 
energy  sufficient  to  lift  a  million  tons  through  a  height  con- 
siderably exceeding  one  hundred  yards;  and  that  since  the 
amount  of  energy  is  proportional  to  the  number  of  corpus- 
cles comprising  the  atom  of  the  element,  the  energy  of  the 
other  elements  such  as  sulphur,  iron,  or  lead  must  enor- 


INTERATOMIC   ENERGY.  177 

mously  exceed  this  amount.  We  have  already  shown  that 
Professor  Thomson's  calculations  have  a  habit  of  squaring 
with  fact.  The  energy  whence  we  obtain  our  manufactur- 
ing power  whether  derived  from  burning  coal  or  gas  or  any 
other  chemical  reaction  depends  upon  the  action  of  one  sys- 
tem of  atoms  upon  another.  It  is  absolutely  insignificant 
compared  with  the  limitless  energy  locked  up  within  the 
atoms  themselves.  We  know  that  this  energy  exists,  but, 
to-day,  we  have  no  control  over  it.  We  can  neither  set  it 
loose  nor  tie  it  up  in  any  way  whatever.  We  can  only 
observe  it.  But  it  would  be  rash  indeed  to  predict  that  our 
impotence  will  last  forever.  Strange  things  happen  nowa- 
days and  yet  stranger  things  may,  nay  will,  be  seen  by 
future  men.  We  have  no  real  warranty  that  this  infinity 
of  energy  will  be  tapped  by  man,  except  this  :  That  what 
man  earnestly  longs  for  he  will  obtain.  If  he  knows  that 
every  breath  of  air  he  draws  has  contained  within  itself 
power  enough  to  drive  the  workshops  of  the  world  he  will 
find  out  some  day,  some  how,  some  way  of  tapping  that 
energy.  In  looking  for  plausible  methods  of  attacking 
the  problem  we  find  at  least  a  hint.  X-rays  passing 
through  a  substance  cause  it  to  emit  X-rays.  These 
induced  X-rays  are  called  secondary  rays  or  the  S-rays  of 
Sagnac.  They  are  emitted  from  solids,  liquids  and  gases 
whenever  X-rays  fall  upon  them,  and  they  differ  in  charac- 
ter from  the  primary  rays  that  produce  them.  They  are 
not  pure  X-rays  for  they  consist  of  corpuscles  as  well,  and 
since  some  of  the  radiation  is  exceedingly  easily  absorbed, 
it  is  likely  that  alpha  particles  are  present  also.  If  this  is 
the  case  it  is  difficult  to  see  why  we  should  not  call  a  body 
lying  under  the  impact  of  X-rays,  radio-active ;  and  if  the 
body  becomes  radio-active  in  this  way,  it  is  a  moot  point, 
indeed,  as  to  whether  the  energy  of  the  radiating  substance 
12 


178  THE   NEW  KNOWLEDGE. 

is  not  greater  than  the  energy  of  the  X-rays  falling  upon 
it — the  excess  of  energy  being  derived  from  re-arrange- 
ments taking  place  in  the  atoms  of  the  body  exposed  to  the 
primary  X-ray  bombardment.  It  is  conceivable  that  some 
such  method  of  attack  might  lead  to  a  way  of  doing  by  ex- 
ternal agency  what  radio-active  bodies  can  do  spontaneously, 
i.  e.,  liberate  the  energy  locked  up  in  the  atom.  It  has 
been  playfully  suggested  by  Professor  Rutherford  that  some 
day  it  might  be  possible  to  construct  a  detonator  which 
would  send  a  wave  of  atomic  disintegration  through  the 
earth  and  decompose  the  whole  round  world  into  helium, 
argon,  and  other  gases,  leaving  literally  not  one  stone  upon 
another.  Without  being  frightened  by  any  such  humorous 
suggestion  as  this,  we  can  easily  grant  that  with  the  con- 
tinuous acceleration  of  scientific  research  where  one  year 
of  the  present  counts  for  a  cycle  of  former  time,  there  will 
come  a  day  in  the  unending  succession  of  days  when  men 
will  look  with  mingled  horror  and  amusement  at  the  burn- 
ing of  coal  and  wood,  and  will  date  the  coming  in  of  their 
kingdom  to  the  time  when  Curie  and  Laborde  demonstrated 
the  existence  and  extent  of  interatomic  energy. 


CHAPTER  IV. 
THE  ELECTRICAL  NATURE  OF  MATTER. 

It  often  happens  that  in  inverting  a  problem  the  truth 
drops  out.  Copernicus,  instead  of  assuming  that  the  sun 
moved  around  the  world,  succeeded  better  by  assuming  that 
the  world  moved  around  the  sun.  Kant,  also,  instead  of 
assuming  that  knowledge  must  conform  to  objects,  inverted 
the  idea  by  assuming  that  objects  must  conform  to  our 
knowledge.  In  a  similar  fashion  it  is  now  proposed  to  in- 
vert the  conception  of  matter  and  electricity  that  we  have 
so  far  gained.  Instead  of  assuming  that  corpuscles  are 
particles  of  matter  possessing  the  properties  of  negative 
electricity,  we  shall  assume,  instead,  that  corpuscles  are  par- 
ticles of  negative  electricity  possessing  the  properties  of 
matter.  It  will  be  seen  that  this  new  way  of  looking  at 
things  will  lead  to  new  knowledge.  It  is  proposed  in  this 
chapter  to  show  by  arguments  adduced  from  facts  that  Mat- 
ter is  made  up  of  Electricity  and  nothing  but  Electricity.  We . 
can  best  develop  the  thesis  by  comparing  matter  and  elec- 
tricity in  the  possession  of  one  common  property.  The  one 
sole  unalterable  property  of  matter  is  inertia.  It  requires 
an  effort  to  put  matter  into  motion  when  the  matter  is  al- 
ready at  rest,  and  it  requires  an  effort  to  stop  matter  after 
it  has  once  been  set  in  motion.  Inertia  is  simply  the  Latin 
word  for  laziness,  but  the  "laziness"  of  matter  is  excep- 
tional and  peculiar.  Matter  hesitates  as  much  to  stop 
when  once  in  motion  as  to  start  when  once  at  rest. 

Matter  hesitates  to  start.     Water  will  reflect  a  cannon 

(179) 


180  THE   NEW  KNOWLEDGE. 

ball  or  flatten  a  bullet.  A  dynamite  charge  exploded  upon 
a  stone  will  shatter  the  stone  before  the  air  has  time  to 
move  away.  Matter  also  hesitates  to  stop.  It  tends  to 
overshoot  the  mark.  A  bullet  will  fly  many  a  yard  after 
it  has  left  the  gun.  In  the  gun  it  was  urged  by  force,  but 
after  it  has  left  the  gun  it  not  only  continues  on  its  way 
without  force  but  against  force,  the  force  of  friction,  until 
eventually  it  is  overcome.  It  is  sometimes  asked:  "Is  per- 
petual motion  possible?"  It  is  not  only  possible  but  neces- 
sary if  there  is  no  interfering  or  opposing  force.  The  inert- 
ness, or  inertia,  of  matter  is  defined  in  the  First  Law  of  Mo- 
tion: "A  body  at  rest  remains  at  rest  and  a  body  in  motion 
continues  to  move  with  a  constant  speed  in  a  straight  line, 
unless  acted  upon  by  some  external  unbalanced  force." 
We  may  illustrate  this  law  by  the  case  of  a  body  which  is 
in  motion  under  a  pair  of  balanced  forces.  Thus,  a  steam- 
ship under  the  application  of  force  does  not  instantaneously 
assume  its  full  velocity;  it  gathers  way. 

After  it  attains  a  constant  speed  it  is  under  the  applica- 
tion of  no  resultant  force  whatever,  the  force  developed  by 
the  engines  simply  overcoming  the  contrary  force  of  the  re- 
sistance of  the  water.  It  is  thus  obeying  the  first  law  of 
motion.  On  the  cessation  of  the  force  from  the  engines,  the 
hitherto  balanced  force  of  friction  begins  to  be  effectual 
and  the  ship  stops,  not  at  once  but  gradually.  Now 
this  property  of  inertia  which  causes  the  steamship  to  act 
in  this  way  belongs,  also,  to  electricity.  The  inertia  of  elec- 
tricity is  called  self-induction.  When  a  current  of  electricity 
is  suddenly  started  in  a  wire  it  does  not  rise  to  its  full 
strength  instantaneously.  Just  like  the  steamship  it  re- 
quires a  certain  time  to  gather  way  and  to  rise  to  its  full 
strength.  Again,  when  the  current  is  suddenly  broken,  it 
does  not  stop  instantaneously  but  tends  to  persist.  This  tend- 


THE  ELECTRICAL  NATURE  OF  MATTER.       181 


ency  to  persist  is  interesting.  This  sudden  breaking  of  a  cur- 
rent gives  rise  to  an  electrical  push,  or  electro-motive  force, 
far  greater  than  that  which  maintained  the  current.  The 
instant  the  circuit  is  broken  there  is  a  sudden  lurch  forward 
of  the  current  which  enables  it  to  spring  across  the  break 
and  which  gives  rise  to  the  spark  seen  at  that  point.  The 
more  sudden  the  break  the  more  violent  is  the  spark.  This 
is  very  like  the  blow  which  a  high-pressure  service  water- 
tap  experiences  when  the  flow  of  water  is  suddenly  arrested 
by  turning  the  tap.  The  jar  of  the  water  momentum  will 
sometimes  burst  the  pipe.  The  delay  of  the  current  on 
making  the  circuit,  and  its  tendency  to  persist  after  break- 
ing it,  prevents  any  very  sudden  change  in  the  strength  of  a 
current.  It  is  this  that  hinders  telephonic  communication 
through  very  long  wires  and  renders  ocean  cable  telegraphy 
a  comparatively  slow  operation.  In  the  past,  this  refusal  of 
an  electric  current  to  undergo  any  very  sudden  change  has 
been  called  the  phenomenon  of  self-induction  or,  sometimes, 
quasi-electrical-inertia.  We  propose,  now,  to  eliminate  both 
the  quasi  and  electrical  and  to  develop  the  idea  that  this  un- 
willingness of  an  electrical  current  to  start  or  stop  is  the 
unwillingness  of  matter  to  start  or  stop.  That,  in  each  case, 
the  phenomenon  is  due  to  simple  inertia,  and  that  that  in- 
ertia is  purely  electrical  in  its  nature. 

The  idea  that  inertia  is  electrical  in  its  origin  first  took 
form  in  a  paper  by  J.  J.  Thomson,  which  appeared  in  the 
Philosophical  Magazine  for  1881,  and  which  has  since  be- 
come classical.  This  paper  dealt  with  the  properties  of  a 
moving  charged  sphere,  and  in  it  Professor  Thomson  showed 
that  an  electrical  charge,  concentrated  on  such  a  moving 
sphere,  must  possess  inertia  due  to  the  electro-magnetic 
field  of  force  which  it  creates  by  its  motion  in  the  surround- 
ing ether.  In  other  words,  it  will  tend  to  resist  change  of 


182  THE    XEW   KNOWLEDGE. 

motion,  which  we  understand  to  be  inertia,  and  will  thus 
behave  as  though  its  mass  were  increased.  In  order  that 
this  inertia,  or  increase  of  mass,  should  become  perceptible, 
it  is  necessary  that  the  sphere  should  be  very  small  and 
that  its  speed  should  approach  that  of  light.  We  can  best 
illustrate  this  by  appending  certain  calculations  subse- 
quently made  by  Sir  Oliver  Lodge,  showing  the  extent  to 
which  the  apparent  mass  would  increase  as  the  speed  of 
light  is  approached.  If  1  equals  the  mass  measured  by 
the  inertia  of  the  sphere  under  slow  motions,  at  half  the 
speed  of  light  the  mass  becomes  1.12;  at  three-quarters, 
1.37;  at  nine-tenths,  1.8;  when  the  speed  is  99  per  cent, 
of  that  of  light  the  mass  is  3.28;  at  99.5  per  cent.,  5; 
while  between  this  last  value  ana  that  of  light  the  mass 
increases  to  infinity.  It  is  plain,  then,  that  no  substance 
can  move  faster  than  light;  and  it  is  interesting  to  note 
how  very  near  the  speed  of  light  must  be  approached  be- 
fore the  mass  becomes  increased  to  an  enormous  extent. 
Now,  this  paper  of  Thomson's,  at  the  time  of  its  publica- 
tion, excited  but  little  comment  because  of  the  fact  that 
at  that  time  no  bodies  were  known  which  were  sufficiently 
small  and  sufficiently  swift  in  their  velocity  to  make  this 
increase  in  mass  experimentally  demonstrable.  The  paper 
belonged  to  mathematical  academics.  It  was  not  practi- 
cally important.  With  the  coming,  however,  of  corpuscles, 
the  paper  assumed  a  very  different  aspect.  We  have  in 
corpuscles  particles  very  much  smaller  and  very  much 
lighter  than  the  smallest  and  lightest  atom;  and,  more- 
over, we  have  shown  that  in  the  case  of  radium  these 
particles  are  shot  off  with  velocities  approaching  that  of 
light.  We  have,  then,  in  the  corpuscle  a  means  of  verify- 
ing this  mathematics  and  of  determining,  as  a  matter  of 
material  fact,  whether  or  not  the  mass  measured  by  the 


THE   ELECTRICAL    NATURE    OF  MATTER.  183 

inertia  of  a  body  increases  with  its  velocity.  This  investi- 
gation has  been  carried  out  by  Kaufmann  with  the  most 
interesting  results.  These  results  are  shown  in  the  follow- 
ing table.  The  first  column  expresses  the  relative  veloci- 
ties of  the  particle,  and  the  second  column  the  value  of  the 
fraction  e/m,  where  e  is  the  charge  on  the  particle  and  m 
is  its  mass. 

Value  of  v.  Value  of  e/m. 
2.83  .62 

2.72  .77 

2.59  .975 

2.48  1.17 

2.36  1.31 

AVe  see  by  this  table,  reading  from  bottom  to  top,  that 
the  value  of  e/m  diminishes  as  the  velocity  increases.  We 
learned  in  Part  III,  page  65,  that  the  value  of  e  remains 
constant.  Hence  this  table  indicates  that  the  mass  in- 
creases with  the  velocity.  Kaufmann's  work,  therefore, 
demonstrates,  experimentally,  the  truth  of  Thomson's 
mathematics.  Not  only  so  but  it  affords  Professor  Thom- 
son the  opportunity  of  still  further  extending  the  scope  of 
his  mathematical  conclusions.  In  a  word,  Thomson  cal- 
culates the  ratio  of  the  masses  of  the  rapidly  moving 
corpuscles  given  out  by  radium  to  the  mass  of  the  same 
particles  when  at  rest,  on  the  assumption  that  the  whole  of 
the  mass  is  due  to  the  electrical  charge  upon  it;  and  he  com- 
pares these  results  with  the  values  as  determined  by  Kauf- 
mann's experiments.  The  comparison  is  shown  in  the 
following  table,  where  the  first  column  contains  the  ve- 
locities as  determined  by  Kaufmann,  the  second  column 
the  mathematical  determination  of  the  number  of  times 
the  mass  of  a  particle  moving  with  the  given  velocity  ex- 


184  THE   NEW  KNOWLEDGE. 

ceeds  the  mass  of  the  particle  when  at  rest,  and  the  third 
column  the  same  values  as  found  by  Kaufmann  experi- 
mentally : 

Number  of  times  the  ^ 
mass  of  the  particle 


with  the  given  ve- 
locity exceeds  its 
mass  at  rest. 


ditto. 


Velocity  of  the  Mathematically        Found  by  experi- 

particles.  determined.  ment. 

2.85  3.1  3.09 

2.72  2.42  2.43 

2.59  2.0  2.04 

2.48  1.66  1.83 

2.36  1.5  1.65 

We  see  from  these  results  that  the  calculated  and  the 
experimental  results  practically  agree,  and  we  are,  there- 
fore, entitled  to  believe,  if  we  like,  that  the  whole  mass  of 
the  corpuscle  arises  from  its  electrical  charge.  But  the 
corpuscle  we  deem  to  be  the  constituent  of  an  atom,  the 
atom  the  constituent  of  a  molecule,  and  a  molecule 
the  constituent  of  a  mass  of  matter,  such  as  a  table  or  a 
chair.  Hence,  on  this  view,  the  inertia  of  any  material 
body,  and  the  mass  of  it  as  measured  by  the  inertia,  is 
due  simply  to  electrical  charges  in  motion.  On  this  view, 
then,  the  to-and-fro  motion  of  a  pendulum  and  the  electrical 
oscillations  of  the  spark  from  a  Leyden  jar,  are  simply  two 
manifestations  of  an  identical  thing,  the  inertia  of  a 
charged  body. 

But  what  do  we  mean  by  saying  that  the  mass  of  a 
body  depends  simply  on  an  electric  charge?  By  mass  is 
meant  quantity  of  matter,  and  the  idea  that  the  quantity 


THE  ELECTRICAL  NATURE  OF  MATTER.        185 

of  matter  in  a  body  depends  on  the  speed  with  which  an 
electric  charge  moves,  is  difficult  to  grasp  concretely;  for 
we  are  accustomed  to  think  that  the  quantity  of  any  given 
object  is  invariable.  We  may,  however,  obtain  a  concrete 
representation  of  the  idea  by  considering  the  analogical 
case  of  a  sphere  moving  through  a  frictionless  liquid.  In 
such  a  case,  when  the  sphere  moves,  it  sets  the  liquid 
around  it  moving  with  a  velocity  proportioned  to  its  own, 
so  that  the  sphere  is  accompanied  by  a  definite  volume  of 
the  liquid.  This  volume  is  one-half  the  volume  of  the  i 
sphere  and  the  sphere,  therefore,  behaves  as  though  its 
mass  were  increased  by  that  amount.  In  the  case  of  a 
cylinder  moving  at  right  angles  to  its  length,  the  mass  of 
the  cylinder  is  increased  by  the  mass  of  an  equal  volume 
of  the  liquid.  Now  the  cylinder  in  our  case  is  the  electric 
charge  and  the  frictionless  liquid  is  the  ether.  The  electric 
charge  possesses  no  mass  at  all,  and  the  total  mass,  there- 
fore, is  due  to  the  bound  ether  carried  along  by  the  charge 
in  its  motion,  the  total  amount  of  the  bound  ether  de- 
pending on  the  velocity  of  the  charge.  On  this  view  of 
"  the  electrotonic  theory  of  matter,"  all  mass  is  the  mass 
of  the  ether,  all  momentum,  whether  electrical  or  mechani- 
cal, the  momentum  of  the  ether,  and  all  kinetic  energy 
the  kinetic  energy  of  the  ether. 

The  electrotonic  theory  of  matter  may  be  used,  as  well, 
to  account  for  certain  properties  of  electricity.  Corpuscles, 
used  in  this  connection,  are  generally  given  another  name;  (/ 
they  are  called  electrons.  Since  we  have  used  the  word 
corpuscles  throughout  we  shall  continue  to  use  it  in  this 
connection,  remembering,  however,  that  the  two  words, 
corpuscle  and  electron,  stand  for  the  same  thing  precisely. 
An  electric  current,  for  example,  is  easily  explained  on  the 
corpuscular  theory.  Electricity  may  be  conducted  through 


186  THE    NEW    KNOWLEDGE. 

gases,  liquids  and  solids.  In  gases  the  electricity  is  con- 
veyed by  free  corpuscles,  flying  bullet-like,  and  with  veloci- 
ties amounting,  sometimes,  to  a  hundred  thousand  miles  a 
second.  In  liquids  the  velocity  is  more  nearly  an  inch  an 
hour.  In  liquids,  the  corpuscles  travel  with  the  atoms,  and 
for  this  reason  travel  slowly.  Liquid  conduction  is  what 
Sir  Oliver  Lodge  calls  "  the  bird-seed  method  of  conduction ; " 
for  the  corpuscle  travels  through  the  liquid  from  one  elec- 
trode to  the  other  much  as  a  bird  carries  a  seed.  It  moves 
slowly  because  it  must  jostle  its  way  through  the  throng 
of  other  atoms,  and  also  because  of  the  load  of  the  heavy 
atom  it  conveys.  In  the  case  of  solias,  or  metallic  con- 
duction, the  atoms  are  fixed  in  their  places  relatively  to 
one  another.  Their  only  power  is  that  of  vibration.  The 
corpuscles,  therefore,  can  go  from  one  end  of  the  wire  to 
the  other,  only  by  being  handed  on.  Each  atom  in  the 
string  along  the  wire  receives  one  and  passes  it,  or  another 
like  it,  on  to  the  next,  so  that  for  every  corpuscle  that 
starts  at  one  end  of  the  wire,  another  like  it  passes  out  at 
the  other  end. 

Magnetism,  on  the  basis  of  the  electrotonic  theory,  is  a 
force  developed  at  right  angles  to  the  moving  charge. 
This  magnetism  may  be  seen  in  the  free  corpuscles  flying 
through  a  Crookes'  tube  where  they  may  be  bent  up  and 
down  by  a  magnet;  in  the  beta-rays  from  radium  where 
they  also  fly  free;  or  in  the  magnetism  developed  in  a  wire 
when  corpuscles  are  being  handed  on  through  it  and  con- 
stituting what  we  call  a  current.  Light,  Rontgen  rays 
and  all  other  radiations  result,  and  must  result,  from  dis- 
turbances in  the  surrounding  ether  whenever  the  velocity 
of  the  electric  charge  is  accelerated,  diminished,  stopped 
or  changed  in  direction. 

The  electrotonic  theory  teaches  us: 


THE    ELECTRICAL   NATURE   OF   MATTER.  187 

1.  That    negative   electricity   is   made  up  of   unit   charges 

called  corpuscles. 

2.  That  static  electricity  is  due  to  the  action  of  these  cor- 

puscles at  rest. 

3.  That  current  electricity  is  due  to  nothing  but  these  cor- 

puscles in  motion,  whether  through  gases,  liquids  or 
solids. 

4.  That   magnetism  is  a  force  developed  in  the  ether  as 

right  angles  to  the  direction  of  motion  of  the  cor- 
puscles. 

5.  That  light  and  other  radiations  are  due  to  disturbances 

in  the  surrounding  ether  caused  by  a  change  in  the  mo- 
tions of  the  corpuscles. 

6.  That   the  self-induction  of  an  electric   current  and  the 

mechanical  inertia  of  matter  are  identical,  and  that 
they  are  due  to  the  electric  charge,  or  corpuscle,  in 
motion. 

7.  That  mass,  or  quantity  of  matter,  is  simply  the  ether 

carried  along  by  the  corpuscle  in  its  motion,  that  it  is 
by  no  means  a  constant  quantity  but  depends  upon 
the  velocity  of  motion  of  the  corpuscle. 

8.  That  the  atoms  of  matter,  themselves,  are  made  up  of  the 

same  negative  charges  or  corpuscles,  each  aggregation 
of  corpuscles  being  surrounded  by  a  sphere  of  positive 
electricity. 

9.  That,  consequently,  matter,  in  its  last  analysis,  is  iden- 

tical with  electricity. 

We  see,  then,  that  the  electrotonic  theory  accounts  for 
static  electricity,  current  electricity,  magnetism,  the  radi- 
ations of  light,  X-rays,  etc.,  inertia,  chemical  action,  the 
atoms  of  matter  and  their  peculiar  properties  as  exem- 
plified in  the  periodic  law,  and  the  phenomena  of  radio- 
activity. 


188  THE  NEW  KNOWLEDGE. 

We  must  now  ask  ourselves  the  questions:  1.  Is  it  proved? 
2.  Are  there  any  phenomena  that  the  theory  will  not  ac- 
count for? 

With  regard  to  the  first  question,  we  may  say  at  once, 
the  theory  is  not  proved.  It  is  an  hypothesis  which  ac- 
counts in  a  beautiful  way  for  the  phenomena  enumerated 
above.  It  finds  its  chief  acceptance,  outside  of  this,  in  the 
fact  determined  by  Thomson  that  the  whole  mass  of  mat- 
ter may  be  accounted  for  on  the  supposition  that  it  is  elec- 
trical in  origin.  But  between  the  fact  that  it,  and  all  these 
other  matters,  may  be  accounted  for,  and  the  fact  that  there 
is  nothing  else  in  heaven  and  earth  that  will  account  for  it 
instead,  there  is  a  great  gulf  fixed.  The  acceptibility  of 
the  hypothesis  depends  on  the  extent  of  its  exclusive  power 
to  account  for  things;  the  more  exclusive  it  becomes  the 
more  we  shall  believe  it.  In  the  meantime,  while  it  is  cer- 
tainly extraordinary  in  its  power  to  explain,  the  answer  to 
our  second  question  bids  us  be  cautious.  There  are  phe- 
nomena which  the  theory  does  not  yet  explain.  For  ex- 
ample what  is  positive  electricity,  as  distinguished  from 
negative  which  consists  of  these  corpuscles?  The  answer  is, 
we  do  not  know.  We  conceive  of  an  atom  as  an  aggrega- 
tion of  negative  corpuscles  arranged  in  a  certain  number  in 
a  certain  way,  and  surrounded  by  a  sphere  of  positive  elec- 
tricity which  balances  the  negative  electricity  of  the  cor- 
puscles within  it.  We  can  account  for  positive  electrifica- 
tion as  distinct  from  positive  electricity  on  the  supposition 
that  a  positively  electrified  body  is  one  which  has  lost  some  of 
its  corpuscles  while  a  negatively  electrified  body  is  one  which 
has  gained  corpuscles.  But  this  does  not  tell  us  what  posi- 
tive electricity  actually  is.  If  it  is  made  up  of  particles,  these 
particles  must  either  have  no  mass  at  all,  or  very  little,  for  the 
mass  of  the  whole  atom  seems  to  be  simply  the  sum  of  the 


THE   ELECTRICAL   NATURE    OF  MATTER.  189 

masses  of  its  negative  corpuscles.  Positive  electricity  as 
apart  from  an  atom  does  not  seem  to  exist.  It  never  seems 
to  fly  free  as  the  corpuscle  does.  Its  nature  is,  to-day, 
a  mystery. 

What  is  gravitation?  Again,  the  answer  is  not  forth- 
coming. The  force  of  gravitation  is  minute  and  it  is  only 
apparent  to  us  because  of  the  nearness  to  us  of  the  over- 
whelming mass  of  the  earth.  Still  it  ought  to  be  capable 
of  explanation  and  the  explanation  has  not  yet  arrived. 

Still,  again,  what  are  Life  and  Mind?  There  is  nothing  in 
the  foregoing  pages  to  give  us  even  the  glimpse  of  an  idea 
of  the  physical  basis  of  Life.  It  is  unreasonable,  however, 
to  expect  too  much  for  a  theory  still  in  its  infancy,  and  we 
can  afford  to  marvel  at  the  mysteries  which  it  does  explain, 
and  to  give  it  on  this  amount  a  large  measure  of  accept- 
ance. 

It  ought  to  be  pointed  out  at  the  end  of  this  chapter 
that  the  theory  of  atomic  disintegration  is  quite  independent 
of  the  electrotonic  theory  we  have  been  considering. 
Atomic  disintegration  postulates  nothing  beyond  the  con- 
ception, familiar  to  chemists  for  the  last  hundred  years,  that 
atoms  exist.  Once  grant  the  existence  of  the  chemist's 
atom  and  the  disintegration  of  the  atom  necessarily  follows. 
Neither  has  it  any  necessary  connection  with  the  facts  of 
radio-activity,  the  transmutation  of  the  elements,  or  the 
vast  stores  of  inter-elemental  energy. 


PART  VI. 


INORGANIC  EVOLUTION. 


PART  VI. 
INORGANIC  EVOLUTION. 


CHAPTER  I. 
CELESTIAL  DISSOCIATION. 

The  products  of  the  dissociation  of  the  heavy  atoms  such 
as  radium  and  uranium  render  the  air  a  conductor  of  elec- 
tricity and  this  conductivity,  and  hence  the  dissociation 
which  causes  the  conductivity,  is  measurable  by  the  elec- 
troscope. The  electroscope  is  hundreds  of  thousands  of 
times  more  sensitive  than  the  most  refined  type  of  spec- 
troscope in  existence.  This,  however,  should  not  detract 
from  the  admiration  which  is  due  to  the  spectroscope.  In 
the  same  measure  that  the  electroscope  exceeds  in  sensi- 
tiveness the  spectroscope  so  does  the  spectroscope  exceed 
any  other  known  instrument  for  the  detection  and  mensu- 
ration of  minute  quantities  of  matter.  Besides,  the  elec- 
troscope is  exceedingly  limited  in  its  application  while  the 
range  of  the  spectroscope  is  as  wide  as  the  universe.  That 
the  spectroscope  will  detect  the  millionth  of  a  milligram  of 
matter,  and  on  that  account  has  discovered  new  elements, 
commands  our  admiration;  but  when  we  find,  in  addition, 
that  it  will  detect  the  nature  of  forms  of  matter  billions  of 
miles  away  and,  moreover,  that  it  will  measure  the  velocities 
with  which  these  forms  of  matter  are  moving,  with  an  ab- 
surdly small  per  cent,  of  possible  error,  we  can  easily  ac- 
quiesce in  the  statement  that  it  is  the  greatest  instrument 
13  (193) 


194  CELESTIAL  DISSOCIATION. 

ever  devised  by  the  brain  and  hand  of  man;  and  that  if 
we  are  to  win  additional  knowledge  of  elemental  dissocia- 
tion as  it  exists  in  the  sun  and  stars,  the  spectroscope  is 
our  one  sole  means  to  that  end. 

On  a  priori  grounds  we  should  rather  expect  to  find  this 
dissociation.  For  the  elements  which  dissociate  on  earth, 
thorium  for  example,  are  in  their  normal  chemistry,  in  no 
wise  remarkable  or  particularly  distinguished  from  other 
elements.  The  other  elements,  therefore,  ought  to  dis- 
sociate under  favorable  conditions.  Now,  it  is  in  the  sun 
and  stars  that  we  shall  find  these  favorable  conditions  if 
anywhere;  for  they  constitute  furnaces  with  temperatures 
enormously  high  and  transcendental  so  far  as  man  may 
hope  to  attain.  The  spectroscope  with  which  we  shall 
search  for  this  celestial  dissociation  is,  in  its  essentials,  sim- 
ple in  the  extreme.  The  fundamental  part  of  the  instru- 
ment is  a  prism  of  glass  or  a  grating.  The  light  from  the 
body  Bunder  examination  is  passed  through  a  fine  slit  and 
hence  through  the  prism.  The  prism  sifts  out  the  light  so 
that  the  longest  or  "  red  "  waves  go  to  one  side  and  the 
shortest  or  "violet"  waves  to  the  other.  Each  kind  of 
light  thus  yields  its  own  individual  image  of  the  slit  in  the 
form  of  a  fine  line.  All  incandescent  solids,  liquids,  and 
some  dense  gases  on  becoming  incandescent  give  out  white 
light  consisting  of  waves  of  every  conceivable  length  and 
hence  instead  of  separate  little  line-like  images  there  results 
an  infinity  of  images  all  blended  together  into  a  broad  band 
ranging  by  imperceptible  gradations  through  red,  orange,  yel- 
low, green,  blue  and  violet.  Such  a  band  of  color  is  called 
a  continuous  spectrum.  Fig.  45.  If,  now,  we  pass  from 
incandescent  solids  and  liquids  to  substances  which  easily 
volatilize,  the  light  from  their  flames  presents  a  very  dif- 
ferent appearance.  We  find,  in  fact,  that  it  consists  of  a 


CELESTIAL   DISSOCIATION. 


195 


copious  emission  of  light  of  a  few  wave-lengths  only,  the 
others  being  missing.     The  result  of  this  is  that  instead  of 


Candle-flame  spectrum. 


Straight  slit. 


Ring  slit. 


Spirit 

lamp  flame 
with  salt. 


Fig.  45.     A  continuous  and  a  discontinuous  spectrum. 

a  broad  band  of  colour,  we  see  a  series  of  lines  of  definite 
colour  and  separated  by  definite  spaces.  Such  a  series  of 
definite  lines  is  called  a  discontinuous  or  line  spectrum.  No 
two  elements  emit  the  same  light,  and  hence  no  two  ele- 
ments yield  the  same  line  spectrum.  It  is  therefore  possible 
to  recognise  each  element  by  the  spectrum  of  its  lines  when 
sifted  out  by  the  prism  and  this  process  is  called  spectrum 
analysis.  It  makes  no  manner  of  difference  whether  the 
element  exists  on  the  earth,  in  the  sun  or  in  the  farthest 
"fixed "  star.  Its  existence  may  be  recognised  beyond  dis- 
pute wherever  light  shines  from  it  to  us.  Fig.  46.  In  the 


B 


Fig.  46.     Parts   of  the    spectra  of .  (A)    barium   and  (B)  iron  (from  a 

photograph). 


196 


THE   NEW   KNOWLEDGE. 


case  of  some  elements,  the  lines  of  the  spectrum,  instead 
of  being  irregularly  distributed,  are  arranged  rythmically 
so  that  in  appearance  they  strongly  resemble  a  Corinthian 
column  seen  under  a  strong  side  light.  Such  line  spectra 
are  called  fluted  spectra.  The  spectrum  of  carbon  is  a 
beautiful  and  typical  example  of  fluted  spectra.  Fig.  47. 


Fig.  47.     Fluting  of  carbon. 

« 

In  the  case  of  certain  elements,  again,  the  lines  arrange 
themselves  in  accordance  with  a  beautiful  law  in  such  a 
fashion  that  they  constitute  a  sequence  numerically  related 
to  one  another.  Such  a  sequence  of  rythmically  related 
lines  is  called  a  series.  Fig.  48. 


Violet 


Red 


Fig.  48.     The  series  in  the  cleveite 


(  KLKSTIAL   DISSOCIATION.  197 

The  lines  constituting  the  discontinuous  spectrum  of  an 
element,  as  normally  produced,  are  bright  lines;  that  is,  they 
have  definite  colours.  In  the  beginning  of  the  last  century 
Fraunhofer  discovered  that  the  continuous  band  of  color 
constituting  the  spectrum  of  sunlight  was  broken  by  a 
great  number  of  lines  as  in  the  case  of  a  discontinuous 
spectrum,  but  that  these  lines  were  dark  instead  of  light. 
The  explanation  of  this  lay  in  the  fact  that  the  great  mass 
of  the  highly  heated  interior  of  the  sun  gives  rise  to  light 
of  every  conceivable  wave-length  constituting  the  continuous 
spectrum,  and  that  the  incandescent  gases  surrounding 
this  heated  interior  have  the  selective  power  of  absorbing 
the  very  light-waves  they  themselves  emit  and  thus  give 
rise  to  dark  lines  which,  if  it  were  not  for  the  heated  in- 
terior of  the  sun,  would  be  bright.  These  dark  line  spectra 
are  called  Fraunhofer's  lines.  Fig.  49.  They  constitute  the 
spectra  of  all  the  incandescent  gaseous  substances  existing 
in  the  atmosphere  of  the  sun.  Lines  of  the  spectrum  of 
any  one  substance  in  this  atmosphere  occupy  the  same 
relative  positions  as  they  do  upon  earth  and  hence  the  sub- 
stance may  be  recognized  with  as  much  certainty  as  though 
it  existed  in  the  laboratory  instead  of  93,000,000  miles  away. 

With  these  definitions  we  are  now  in  a  position  to  take 
up  the  business  of  our  subject — the  question  as  to  whether 
or  not  the  elements  exist  in  decomposed  simpler  forms  in 
the  sun  and  stars.  The  work  done  on  this  subject  com- 
prises forty  years  of  the  life  of  Sir  Norman  Lockyer. 
Other  men  have  made  their  contributions,  both  directly 
and  indirectly,  but  Lockyer  has  been  the  foremost  champion 
of  the  idea  and  to  him  alone  belongs  the  chaplet  of  the 
victor.  One  of  the  first  tasks  put  before  Lockyer  in  the 
pioneering  stage  of  his  work  was  the  removal  from  the 
mind  of  science  of  a  serious  misconception.  Men  were 


198 


THE  NEW  KNOWLEDGE, 


CELESTIAL  DISSOCIATION.  199 

deeply  imbued  with  the  idea  that  an  element  could  have 
one,  and  only  one,  spectrum.  They  held  this  idea  because, 
while  not  formally  saying  so,  they  believed  that  the  atom 
which  caused  the  spectrum  was  a  simple  undecomposable 
thing.  This  idea  of  one  element — one  spectrum  was  a 
serious  mistake,  for  it  has  been  possible  to  show  that  an 
element  may  have  two  or  three  spectra  under  different  con- 
ditions,— though  each  spectrum  is  characteristic  for  that 
substance.  Thus,  Plucker  and  Hittorf  in  1865  announced 
that  "  there  is  a  certain  number  of  elementary  substances 
which  when  differently  treated  furnish  two  kinds  of  spectra 
of  quite  a  different  character,  not  having  any  line  or  band 
in  common."  This  was  the  first  blow  to  the  current  con- 
ception though  it  took  many  more  before  the  fact  won  the 
concensus  of  scientific  belief.  The  conditions  under  which 
a  substance  must  bs  placed  in  order  that  its  spectrum  may 
change  from  one  form  to  another  are  as  follows: 

a.  The  temperature  of  a  flame. 

b.  The  temperature  of  the  electric  arc. 

c.  The  vibration  due  to  an  electric  spark  of  very  high 
potential. 

These  three  conditions,  which  amount  to  three  stages  in 
temperature,  give  rise,  in  the  case  of  many  elements,  to 
three  or  more  different  spectra. 

Let  us  take  the  case  of  iron,  according  to  Lockyer: 

1.  The  flame  spectrum  consists  of  a  few  lines  and  flut- 
ings,  only,  including  several  well-marked  lines,  some  of  them 
arranged  in  triplets. 

2.  The  arc  spectrum  consists,  according  to  Rowland,  of 
2,000  lines  or  more. 

3.  The  spark  spectrum  differs  from  the  arc  spectrum  in 
the  enhancement  of  some  of  the  short  lines  and    in  the 
reduced  relative  brightness  of  others. 


200  THE   NEW   KNOWLEDGE. 

4.  A  spectrum  consisting  of  a  relatively  very  small  num- 
ber of  lines  which  are  intensified  in  the  spark. 

We  see,  thus,  that  the  spectrum  of  an  element  depends 
upon  the  temperature  to  which  it  is  subjected,  and  if  we 
ask  ourselves  the  meaning  of  the  change  which  the  spectrum 
undergoes,  it  is  difficult  to  imagine  any  other  efficient  cause 
than  elemental  dissociation  with  increasing  temperature  to 
account  for  it.  But  other  explanations,  more  or  less  spe- 
cious, may  be  assigned,  and  as  the  dissociation,  if  it  exists, 
exists  for  the  briefest  possible  time  under  the  immediate  in- 
fluence of  the  arc  or  spark,  it  is  impossible  to  prove  it. 
Help,  however,  is  found  in  another  direction.  As  Lockyer 
says: 

"  For  twenty  years  I  longed  for  an  incandescent  bottle 
in  which  to  store  what  the  centre  of  the  spark  produces. 
The  stars  have  provided  it." 

The  sun  and  stars  really  constitute  so  many  "  incandes- 
cent bottles  "  in  which  to  study  the  variations  of  spectra 
under  different  conditions  and  afford,  as  we  shall  see,  proof 
of  the  most  reasonable  sort  of  the  dissociation  of  the  ele- 
ments. 

THE   CASE   OF  IRON  IN   THE   SUN. 

In  one  part  of  the  sun,  called  the  "  reversing  layer,"  the 
spectrum  of  iron  is  represented  by  nearly  a  thousand  lines. 
In  another  part  of  the  sun,  called  the  "  chromosphere," 
which  is  apparently  at  a  much  higher  temperature,  the 
spectrum  of  iron  is  reduced  to  two  lines  only.  It  is  dif- 
ficult to  see  what  other  explanation  we  can  assign  to  this 
remarkable  fact  than  that  at  the  higher  temperature  of  the 
chromcsphere  the  atom  of  iron  is  decomposed  or  dissociated 
into  some  simpler  constituent  which  appears  at  that  point. 
This  explanation  is  rendered  additionally  valid  by  the 


CELESTIAL   DISSOCIATION  201 

further  fact  that  in  sun-spots  one  set  of  iron  lines  is  found, 
and  in  this  chromosphere,  quite  another. 

Furthermore,  at  the  maximum  sun-spot  period  the 
widened  sun-spot  lines  are  nearly  all  unknown;  at  the 
minimum  sun-spot  period  they  consist  of  iron  and  other 
well-known  substances,  a  fact  only  to  be  explained  on  the 
assumption  that  the  increased  energy  at  the  maximum  sun- 
spot  period  is  adequate  to  break  the  "  iron  and  other 
well-known  substances"  into  finer  things.  The  most  inter- 
esting evidence,  however,  of  the  decomposition  of  iron  un- 
der the  fervent  heat  of  the  sun  is  adduced  from  the  fact 
that  while  some  of  the  "  iron  "  lines  in  the  sun  show  that 
the  substance  giving  rise  to  them  is  in  rapid  motion,  other 
different  and  adjacent  "iron"  lines  show  that  the  sub- 
stance in  causal  connection  with  them  is  at  rest.  Now,  if 
the  "up-rush"  and  "down-rush"  of  incandescent  gas  in 
the  sun  were  caused  by  iron  vapour  as  iron,  it  should  be 
registered  equally  by  all  the  iron  lines  alike.  The  fact  that 
it  is  not  gives  us  every  reason  to  suppose  that  in  the  sun, 
"  we  are  not  dealing  with  iron  itself,  but  with  primitive 
forms  of  matter  contained  in  iron  which  are  capable  of 
withstanding  the  high  temperature  of  the  sun,  after  the 
iron  observed  as  such  has  been  broken  up." 

Fig.  50,  according  to  Lockyer,  shows  the  variations  in  the 
line  spectrum  of  iron  as  they  existed  in  the  reversing  layer 
of  the  sun,  the  electric  arc,  the  high-potential  electric 
spark,  in  sun-spots  observed  at  Kensington,  and  in  solar- 
prominences  observed  at  Palermo.  It  will  be  observed  that 
the  normal  Fraunhofer's  lines  of  iron  in  the  sun  correspond 
to  the  spectrum  of  iron  as  obtained  at  the  temperature  of 
the  arc,  while  the  iron  spectrum  in  sun-spots  or  solar  storms 
corresponds  to  the  more  strenuous  conditions  of  the  high- 
potential  spark. 


202 


THE  NEW  KNOWLEDGE. 


CELESTIAL  DISSOCIATION. 


203 


Fig.  51,  according  to  the  same  authority,  shows  the  dif- 
ferent rates  of  motion  registered  by  different  and  adjacent 
iron  lines  in  the  sun. 


THE    CASE    OF  MAGNESIUM. 

The  difference  between  the  flame  spectrum  of  magnesium 
and  the  spark  spectrum  is  marked.  Some  of  the  flame  lines 
disappear  altogether,  and  two  new  lines  make  their  appear- 


204  THE    M:\\     KNOWLEDGE. 

ance  in  the  spark.  Turning  to  the  sun,  we  find  that  the 
lines  characteristic  of  the  flame  spectrum  do  not  appear, 
while  some  of  the  spark  lines  do.  Magnesium,  therefore, 
takes  its  place  beside  iron  as  an  element  which,  in  the  sun, 
exists  in  a  dissociated  form;  or,  at  any  rate,  that  is  the 
only  explanation  which  will  render  the  results  consistent 
with  reason. 

THE    CASE   OF  CALCIUM. 

The  evidence  of  dissociation  in  the  sun  afforded  by  cal- 
cium is  interesting.  In  the  electric-arc  spectrum  of  cal- 
cium, a  certain  blue  line  is  particularly  prominent,  while 
two  other  lines,  named  H  and  K  respectively,  are  thin. 
In  the  solar  spectrum,  on  the  other  hand,  the  II  and  K 
lines  of  calcium  are  particularly  thick,  while  the  blue  line 
is  thin.  Again,  in  solar  storms  the  blue  line  of  calcium  is 
always  absent,  while  the  H  and  K  lines  of  the  element  are 
almost  always  seen.  Still  again,  the  blue  line  is  absent  in 
eclipses,  while  the  H  and  K  lines  are  the  brightest  seen  or 
photographed.  Finally,  in  photographing  the  spectra  of 
sun-spots  it  was  discovered  that  the  H  and  K  lines  of 
calcium  are  reversed  or  darkened,  while  the  blue  line  is 
not  reversed.  It  must  be  obvious,  then,  from  this  evidence4 
that  the  calcium  which  on  earth  yields  all  three  lines,  must 
in  the  sun  be  decomposed  into  at  least  two  sub-substances, 
one  of  which  is  in  causal  connection  with  the  blue  line 
and  the  other  with  the  H  and  K  lines. 

STELLAR  EVIDENCE. 

But  evidence  is  found  in  other  suns.  The  spectra  of 
the  stars  afford  in  many  cases  the  same  simplified  spectra 
observed  in  the  sun,  of  iron,  magnesium  and  calcium.  In 
addition,  simplified  spectra  of  other  metals  arc  discovered, 
such  a.-  titanium,  copper,  manganese,  nickel,  chromium, 


CELESTIAL   DISSOCIATION.  205 

vanadium  and  strontium.  To  these  supposably  broken- 
down  metals  the  prefix  proto  is  applied.  By  pro  to-iron, 
proto-copper  and  proto-nickel,  for  example,  is  meant  the 
constituents  of  iron,  copper  and  nickel  as  they  exist  in  the 
sun  or  hottest  stars.  A  very  important  proto-element  is 
proto-hydrogen,  discovered  some  time  ago  by  Professor 
Pickering  of  Harvard  University,  in  the  star  named  zeta- 
Puppis  in  the  constellation  Argo.  The  spectral  lines  rep- 
resenting this  substance  Pickering  at  first  supposed  to 
signify  a  new  element;  but  he  was  able  to  show,  later, 
that  they  belonged  to  a  new  series  of  hydrogen  lines  con- 
stituting a  form  of  hydrogen  unknown  on  earth.  Subse- 
quently, this  same  proto-hydrogen  was  discovered  in  the 
stars  29  Canis  Major  and  gamma-Argus.  It  is  interesting 
to  note  that  this  broken-down,  or  proto-hydrogen,  is  con- 
fined to  the  very  hottest  stars  known. 

If  we  accept  the  dissociation  hypothesis,  these  curious 
proto-spectra  are  naturally,  simply,  and  sufficiently  ex- 
plained. If  we  reject  it,  we  shall  look  in  vain  for  any  other 
present-day  explanation  which  will  co-ordinate  and  har- 
monize the  observed  results. 

In  our  studies  of  the  periodic  law  and  radio-activity,  we 
found  reason  to  believe  that  the  elements  were  not  by  any 
means  the  simple  bodies  formerly  believed  in,  but  that  the 
atoms  of  these  elements  were  highly  complex  and  were  built 
up  of  particles  finer  still.  We  saw  reason  to  believe  that 
in  the  solar  and  stellar  furnaces,  if  anywhere,  we  should  find 
these  sub-elemental  forms  of  matter  existing  in  a  stable 
form,  and  that  we  do  find  a  series  of  remarkable  phenomena 
which  can  be  explained  only  on  the  supposition  that  we 
previously  had  every  reasonable  reason  to  believe,  surely 
strengthens  and  rivets  tight  the  whole  hypothesis  of  the  res- 
olution of  the  atom. 


CHAPTER  II. 
INORGANIC  EVOLUTION. 

In  the  preceding  chapter  we  attempted  to  show  by  a  brief 
exposition  of  the  work  of  Sir  Norman  Lockyer  that  many 
of  the  elements  of  matter  as  they  exist  in  the  sun  and  stars 
are  different  from,  and  simpler  than,  these  same  elements  as 
we  know  them  on  earth.  These  simplified  substances  are 
called  proto-elements  and  the  process  by  which  they  are 
produced  is  dissociation  owing  to  the  super-intensity  of  the 
solar  and  stellar  heat. 

We  now  propose  to  show  in  accordance  with  the  work  of 
the  same  investigator  that  this  dissociation  according  to  tem- 
perature results  in  a  stupendous  evolution  of  inorganic  mat- 
ter, besides  which  organic  evolution  is  the  affair  of  a  day, 
and  to  which  it  is  a  mere  appendix. 

By  organic  evolution  we  mean  that  the  vast  multitudes 
of  plants  and  animals  as  they  exist  to-day  are  not  specially 
created  but  that  they  have  all  resulted  from  older,  simpler 
forms,  and  these  from  simpler  still,  and  these  again  from 
still  simpler,  down  and  down  to  some  ancient  simple  type 
from  which  they  have  all  probably  evolved.  So  by  inorganic 
evolution,  we  mean  that  the  eighty  odd  elements  of  matter 
as  we  know  them  on  earth  to-day  were  not  specially  created, 
but  that  like  the  plants  and  animals,  they  have  truly  evolved, 
from  simpler,  and  still  simpler,  types  back  to  some  really 
simple  element  from  which  they  have  all  evolved  through 
infinite  aeons  gone  by.  Futhermore  we  wish  to  show  that 
(206) 


INORGANIC  EVOLUTION.  207 

the  evolution  of  living  things  is  not  parallel  to,  but  the  con- 
tinuation and  end  of,  the  inorganic  evolution.  We  deem  that 
the  governor  of  this  inorganic  evolution  is  temperature,  and 
that  the  evolution  itself  results  from  a  running  down  of 
temperature.  Before  proceeding  to  the  evidence  for  this 
statement  we  must  first  present  the  basis  upon  which  rests 
the  whole  building  of  Lockyer's  proof.  Before  speaking  of 
"hottest  suns"  and  "cooler  suns"  we  must  have  some  sys- 
tem of  celestial  thermometry  by  which  we  may  compare 
beyond  peradventure  their  relative  temperatures.  The 
basis  upon  which  this  rests  is  strong  and  simple.  We  know 
from  actual  observation  that  on  heating  an  iron  rod,  let  us 
say,  it  first  becomes  red  hot  and  then  proceeds  gradually 
up  to  whiteness.  Now,  if  we  examine  with  a  spectroscope 
the  light  from  the  rod  in  its  progression  to  white  heat,  we 
find  first  that  only  the  red  end  of  the  spectrum  is  seen;  on 
further  heating,  the  orange  and  yellow  portions  of  the  spec- 
trum appear  and,  finally,  at  a  white  heat,  we  have  the 
whole  visible  spectrum  from  red  to  violet.  Not  only  so, 
but  by  the  aid  of  photography  we  discover  that  as  the  rod 
grows  still  hotter  the  spectrum  proceeds  farther  and  farther 
into  the  invisible  portion  of  the  spectrum  beyond  the  violet. 
We  can,  thus,  make  this  general  statement,  that  the  hotter 
a  body  is  the  more  does  its  spectrum  lengthen  out,  the  more 
does  it  extend  from  red  into  the  ultra  violet,  and  this  is  as 
true  of  a  star  as  a  poker. 
Lockyer  first  divides  the  stars  into  three  main  groups: 

Gaseous  stars Longest  Spectrum. 

Metallic  stars Medium  Spectrum. 

Carbon  stars Shortest  Spectrum. 

And  on  the  basis  of  the  foregoing  fact  he  draws  the  following 
deduction: 


208  THE   M:\V   KNOWLEDGE. 

Gaseous  stars Highest  temperature. 

Metallic  stars Medium  temperature. 

Carbon  stars Lowest   temperature. 

Next,  on  examining  the  chemical  constitution  of  these 
three  groups,  he  is  able  to  still  further  extend  our  knowl- 
edge and  the  foregoing  scheme. 

Gaseous  stars  .  .  Highest    temperature  ....  Strong  gas  of 

the  Helium 
family  and 
faint  enhanc- 
ed lines. 
Feeble  gas  of 
Helium  family 
and  strong  en- 


Metallic  stars  .  .  Medium    temperature 


hanced  lines. 
No    gas    of 


Helium  family 
and    strong 
arc  lines. 
Carbon    stars  .  .  Lowest     temperature  ....  Faint  arc  lines. 

The  meaning  of  the  foregoing  table  is  briefly  this:  In  the 
very  hottest  stars  we  find  almost  exclusively  the  gases  hy- 
drogen, helium,  and  the  gas  asterium,  which  is;  so  far,  un- 
known on  earth. 

In  the  stars  of  medium  temperature,  these  gases  become 
replaced  by  metals  in  the  dissociated  state  in  which  they 
exist  in  an  electric  spark  of  extremely  high  potential.  In 
the  stars  of  the  lowest  temperature  the  gases  disappear 
almost  entirely  and  the  metals  exist  in  the  state  produced 
by  the  electric  arc.  So  rigourous  is  this  division  that  Lock- 
yer  has  been  able  to  construct  a  relative  temperature  table 
of  stars  in  which  the  stars  are  arranged  in  the  order  of  de- 


INORGANIC   EVOLUTION.  209 

scending  temperatures,  and  which  constitutes  a  veritable 
stellar  thermometer  which  he  can  use  to  test  the  tempera- 
ture of  the  stars. 

Hottest  stars. 

1.  Two  in  Argo  (zeta  Puppis  and  gamma  Argus). 

2.  Alnitam  (epsilon  Orionis). 

Stars  of  intermediate  temperature. 

3.  Achernar. 

4.  Algol. 

5.  Markab. 

6-  (  ). 

7.  Sirius. 

8.  Procyon. 

9.  Arcturus. 

Stars  of  lowest  temperature. 

10.  19  Piscium. 

Considering  this  star  table  from  hottest  to  coldest  in  re- 
lation to  the  chemical  nature  of  the  stars  comprising  it  the 
evolution  of  matter  drops  into  evidence. 

1.  Argonian  Stars. 

Predominant. — Hydrogen  and  proto-hydrogen. 
Fainter. —          Helium,  unknown  substance,  proto-magne- 
sium,  proto-calcium,  asterium. 

2.  Alnitamiam  Stars. 

Predominant. — Hydrogen,  helium,   proto-silicon,  unknown 

substance. 
Fainter. —          Asterium,     proto-hydrogen,     proto-magne- 

sium,    proto-calcium,    oxygen,    nitrogen, 

carbon. 
14 


210  THE  NEW  KNOWLEDGE. 

3.  Achernian  Stars. 

Predominant. — Hydrogen,  helium,  asterium,  oxygen,  nitro- 
gen, carbon. 

Fainter. —  Proto-magnesium,  proto-calcium,  proto-sili- 
con,  unknown  substance,  silicon. 

4.  Algolian  Stars. 

Predominant. — Hydrogen,  proto-magnesium,  proto-calcium, 

helium,  silicon. 
Fainter. —         Proto-iron,    asterium,    carbon,    proto-titan- 

ium,      proto-copper,      proto-manganese, 

proto-nickel. 

5.  Markabian  Stars. 

Predominant. — Hydrogen,  proto-calcium,  proto-magnesium, 
silicon. 

Fainter. —  Proto-iron,  helium,  asterium,  proto-titan- 
ium,  proto-copper,  proto-manganese, 
proto-nickel,  proto-chromium. 

6.  (  ). 

7.  Sirian  Stars. 

Predominant. — Hydrogen,  proto-calcium,  proto-magnesium, 

proto-iron,  silicon. 
Fainter.—          The  lines  of  the  other  proto-metals  and  the 

arc  lines  of  iron,  calcium  and  manganese. 

8.  Procyonian  Stars. 

Predominant. — Proto-calcium,  proto-titanium,  hydrogen, 
proto-magnesium,  proto-iron,  and  arc  lines 
of  calcium,  iron  and  manganese. 

Fainter.—  The  other  proto-metals  and  metals  occur- 
ring in  the  Sirian  genus. 

9.  Arcturian  Stars. 

Predominant. — Proto-calcium,  arc  lines  of  iron,  calcium, 
and  manganese,  proto-strontium,  hydro- 
gen. 


INORGANIC   EVOLUTION.  211 

Fainter.—          Proto-iron  and  proto-titanium. 

10.  Piscian  Stars. 

Predominant. — Flutings  of  carbon. 
Fainter.—          Arc  lines  of  metallic  elements. 

A  glance  at  the  foregoing  table  shows  us  the  following 
facts: 

1.  That  beginning  with  the   hottest  stars  known,  wrhich 
are  composed  almost  altogether  of  hydrogen  and  dissoci- 
ated hydrogen  we  find  that  as  the  temperature  decreases 
one  after  another  of  the  chemical  elements  makes  its  ap- 
pearance until,  when  we  arrive  at  9,  the  Arcturian  Stars, 
the  elements  rival  in  their  number  those  existing  in  our  own 
sun. 

Now,  since  a  star  has  but  few  elements  when  it  is  hot 
and  many  when  it  is  cold,  the  natural  and  reasonable  ex-  ' 
planation  is  that  the  many  have  evolved  from  the  few. 

2.  Next,  we  find  that  the  metallic  elements  appear  first 
in  the  dissociated  condition  and  afterwards  in  their  normal 
form.    Thus,  in  Group  1  we  have  proto-calcium  which  after 
existing  in  the  intervening  groups  appears  finally  in  Group 
7  in  its  normal  condition  as  the  calcium  which  we  know  on 
earth.     Again,  silicon  appears  in  the  proto-form  in  Group 
2,  in  both  the  proto  and  normal  forms  in  Group  3,  and  in 
the  normal  form  alone  in  Group  4.     Iron   appears  in  the 
proto   form    in  Group   4,    faintly  in   the  normal    form  in 
Group    7,    and    predominantly    in    the    normal    form    in 
Group  8. 

It  is  evident  that  this  fact  greatly  strengthens  the  valid- 
ity of  our  explanation.  For  if  with  decrease  of  temperature 
the  elements  are  evolved  out  of  simpler  substances,  of 
course  the  dissociated  forms  would  appear  first.  It  would 
be  a  serious  blow  to  the  whole  hypothesis  were  we  to  find 


212  THE  NEW  KNOWLEDGE. 

an  element  appearing  first  in  the  normal  form  and  after- 
wards in  the  dissociated  form.  Such,  however,  we  do  not 
find  to  be  the  case. 

3.  Finally,  we  discover  that  as  a  general  rule  the  ele- 
ments of  lightest  atomic  weight  appear  first.  This,  also,  is 
quite  in  accordance  with  what  we  should  expect  on  the 
dissociation  hypothesis.  We  have  had  reason  to  believe  that 
the  atoms  are  built  up  of  nothing  but  corpuscles,  and  these 
corpuscles  would  naturally  form  larger  and  larger  aggrega- 
tions as  the  temperature  sinks.  Furthermore,  in  the 
periodic  law  we  saw  that  the  elements  of  the  same  family 
behaved  just  as  though  the  heavier  atoms  had  evolved  from 
the  lighter.  That  the  elements  do  not  appear  with  sinking 
temperature  strictly  in  the  order  of  their  atomic  weights, 
need  not  discompose  us,  for  we  have  seen  that  a  corpuscular 
aggregation  constituting  an  atom  depends  for  its  stability 
not  only  on  the  number  of  corpuscles  constituting  the  atom, 
but  upon  their  arrangement.  Consequently,  it  might  easily 
be  possible  for  an  aggregation  of  X  corpuscles  with  a 
certain  stable  configuration  to  exist  before  an  aggregation 
of  X-1000  in  a  configuration  less  stable.  This  might  ex- 
plain why  we  find  calcium  in  the  stars  with  an  atomic 
weight  of  40,  before  we  find  sodium  with  a  less  atomic 
weight  of  23.  Though  we  should  expect,  nevertheless,  as 
we  find  to  be  the  case,  that  as  a  general  rule  the  elements 
would  put  in  their  appearance  in  the  order  of  their  atomic 
weights.  Taking  it  altogether  the  evidence  for  an  inor- 
ganic evolution  of  the  elements  seems  every  whit  as  con- 
clusive as  the  evidence  for  an  organic  evolution. 

The  geologist  from  an  examination  of  the  earth's  strata 
from  lowermost  to  highest  finds  an  ever- increasing  com- 
plexity in  the  organic  remains  which  the  rocks  contain. 
The  astronomer  from  an  examination  of  the  stars  from 


INORGANIC    EVOLUTION.  213 

hottest  to  coldest  finds  an  ever-increasing  complexity  in  the/ 
so-called  elements  which  they  contain. 

They  both  deduce  an  evolution  of  simpler  forms  to  more 
complex,  and  their  deductions  are  equally  valid.  We 
accept  the  organic  evolution;  we  must  accept  the  inorganic 
evolution.  Organic  evolution  is  measured  by  millions  of 
years;  inorganic  evolution  is  measured,  probably,  in  billions. 
This  need  not  affright  us  for  we  have  seen  ample  demon- 
stration in  this  book  that  with  God  there  is  neither  great  nor 
small  in  size,  nor  long  nor  short  in  either  distance  or  time. 

But  are  the  organic  and  inorganic  evolutions  parallel  proc- 
esses, or  does  one  follow  upon  the  heels  of  the  other  ? 
We  conceive  of  inorganic  evolution  as  the  existence  first  of 
the  atoms  of  the  dissociated  simplest  elements  followed  by 
the  appearance  of  the  atoms  of  the  elements  more  and 
more  complex  as  the  temperature  diminishes.  From  our 
knowledge  of  every-day  chemistry  we  can  easily  see  that 
the  stellar  bodies  comprising  these  atoms  would  eventually 
sink  to  a  temperature  so  low  that  the  atoms  of  the  elements 
formed  could  associate  into  the  molecules  of  compounds, 
and  that  the  complexity  of  these  compounds  would  con- 
tinually increase  until,  at  about  the  temperature  of  the 
earth,  we  should  find,  as  to-day,  that  they  existed  in  tens 
of  thousands.  But  where  does  life  come  in? 

The  great  law  of  continuity  forbids  us  to  assume  that 
life  suddenly  made  its  appearance  out  of  nothing,  and  tells 
us  that  we  must  look  for  the  element  of  life  in  the  very 
elements  of  matter,  for  the  potentiality  of  life  should  exist 
in  every  atom. 

The  biologists  and  geologists  tell  us  that  life  originated 
in  the  sea.  If  that  is  the  case,  then  the  constituents  of 
living  bodies  should  be  the  constituents  of  the  sea-water 
and  the  air  above  it. 


214  THE  NEW   KNOWLEDGE. 

The  constituents  of  sea-water  are : 

Chloride  of  sodium 77.75 

"  magnesium  ....  10.87 

Sulphate  of  magnesium  .  .  .  .4.73 

"  calcium  .  .  .  .  .  3.60 

"  potassium  ....  2.46 

Bromide  of  magnesium  ....     0.21 

Carbonate  of  calcium  .        .        .        .0.34 

The  main  constituents  of  the  air  are  nitrogen,  oxygen  and 
carbonic  acid. 

The  elements  constituting  sea-water  and  air  are  thus : 

Oxygen,  nitrogen,  carbon,  hydrogen,  sodium,  magnesium, 
potassium,  calcium,  chlorine,  sulphur  and  bromine. 

Let  us  now  examine  the  constituents  of  the  living  being. 
We  find  on  an  ultimate  analysis  that  they  comprise :  Oxy- 
gen, nitrogen,  carbon,  hydrogen,  sodium,  potassium,  phos- 
phorus, sulphur,  calcium,  magnesium,  iron  and  silicon.  We 
see,  thus,  as  a  matter  of  fact,  that  the  elements  constitut- 
ing living  beings  are  almost  exclusively  the  elements  con- 
tained in  sea-water  and  air.  And  not  only  so,  for  the  ele- 
ments constituting  sea-water  and  air  are  the  first  elements 
created  in  the  process  of  inorganic  evolution.  This  is  easily 
determined  by  an  examination  of  the  stellar  temperature 
table,  page  209.  This  table  shows  us  that  the  hydrogen, 
oxygen,  nitrogen,  carbon,  calcium,  magnesium,  iron,  so- 
dium and  silicon  that  constitute  sea-water  and  the  substances 
of  our  own  bodies  are  the  first  born  elements  of  the  hottest 
stars.  More  and  more  do  we  see  that  we  are  the  last  re- 
sult of  a  series  of  consecutive  changes  running  back  without 
any  sudden  break  in  continuity  to  a  time  when  the  stars 
were  young.  Organic  evolution  is  the  last  stage  in  inor- 
ganic evolution  and  we  are  akin  to  the  stars.  It  is  inter- 


INORGANIC   EVOLUTION.  215 

esting  to  notice  the  relation  of  organic  evolution  to  inorganic 
evolution  in  the  scale  of  time  as  illustrated  by  Sir  Norman 
Lockyer.  Fig.  52. 

30000* 

ARGONIAN 

ALNITAMIAN 

29000* 

ACHERNIAN 

ALCOLIAN 

aoooo* 

MARKABIAN 


I5OOO* 

SIRIAN 

PROCYONIAN 

10000* 

ARCTUWAN 


SOOO* 

PISCtAN 
OSM.ftlRID.UELT 
IRON  MELTS 

ORC.EVOL 

Fig.  52.  Diagram  showing  that  organic  evolution  occupies  only  a 
point  in  the  line  representing  the  time  and  temperature  range  required 
by  inorganic  evolution. 


216  THE   NEW   KNOWLEDGE. 

This  diagram  informs  us  that  in  the  running  down  of 
temperature  from  the  30,000  degrees  Centigrade,  which  is 
estimated  as  the  temperature  of  the  hottest  stars,  to  the 
average  temperature  of  the  earth,  that  the  position  of  or- 
ganic evolution  is  a  mere  point  in  the  scale  somewhere  be- 
tween the  temperature  at  which  water  boils  and  ice  melts, 
and  yet  we  measure  that  point  by  many  millions  of  years. 


CHAPTER  III. 
INORGANIC  DEVOLUTION. 

And  so  we  are  akin  to  the  stars,  and  untold  millions  of 
years  ago  the  tiny  particles  of  the  materia  prima,  the  cor- 
puscles, electrons,  or  what  not,  began  the  mazy  configu- 
rations which  evolved  into  the  atoms  which  constitute  us. 
We  began  so  long  ago  that  the  imagination  feels  almost 
willing  to  rest  satisfied  and  satiated  with  a  conception  so 
immense,  —  almost,  but  not  quite.  There  is  a  disturbing 
question.  Did  God,  however  long  ago,  start  the  circling 
particles  with  the  full  plentitude  of  His  energy,  and  then 
leave  them  to  waste  their  energy  in  ever  multiplying  con- 
figurations down  to  what,  however  far  removed  it  may  be, 
must  be  a  state  of  rest  and  death,  or  did  He  give  them  this 
energy  in  perpetuity?  Put  in  another  way,  is  the  universe 
a  clock  wound  up  by  the  Maker  and  left  to  run  itself  clown 
or  has  it  within  itself  the  elements  of  its  own  regeneration? 
The  definite  answer  to  this  great  question  is  hardly  for 
our  day  but  we  have  evidence  which  anticipates  the  an- 
swer, evidence  which  is  strong  and  good  so  far  as  it  goes 
and  which  leads  to  the  conclusion  that  there  is  a  compen- 
sating devolution  of  the  universe  which,  for  all  we  know, 
may  balance  its  evolution. 

Our  belief  in  inorganic  evolution  rests  upon  the  apparent 
fact  that  with  a  running-down  of  temperature  in  the  stars 
we  have  a  continual  increase  in  the  number  of  elements 

(217) 


218  THE   NEW  KNOWLEDGE. 

contained  in  them,  and  the  running-down  of  temperature 
is  measured  by  the  progressive  contraction  of  the  spectra  of 
the  stars  towards  the  red  end  of  the  spectrum.  The  chemical 
constitution  of  the  stars  is  thus  correlated  with  their  tem- 
perature, and  the  stellar  thermometer,  page  209,  is  an  expres- 
sion of  this  correlation.  But  when  Lockyer  had  sorted 
out  his  stars  into  equal-temperature  groups  in  accordance 
with  this  table,  he  discovered  a  fact  of  the  utmost  impor- 
tance and  significance.  He  discovered,  indeed,  that  the 
constituent  stars  of  each  one  of  these  groups  having  among 
themselves  the  same  elements,  the  same  length  of  spectrum 
and,  consequently,  the  same  temperature,  differed  in  this, 
that  while  some  of  them  had  thick  hydrogen  lines  and  thin 
metallic  lines  in  their  spectra,  in  others  the  relative  thick- 
ness and  thinness  of  the  lines  was  reversed.  The  different 
intensities  of  the  hydrogen  lines  in  stars  of  practically  iden- 
tical temperature  and  constitution  is  shown  in  the  accom- 
panying Fig.  53  in  the  case  of  Sirius  and  alpha-Cygni  to- 
gether with  the  differences  in  width  and  intensities  of  the 
enhanced  metallic  lines  hi  two  other  similar  stars  Procyon 
and  gamma-Cygni. 

For  the  full  bearing  of  this  fact  the  reader  is  referred  to 
Lockyer's  "The  Meteoritic  Hypothesis."  Here  it  will  suf- 
fice to  say  that  this  fundamental  difference  of  intensity  in 
the  spectral  lines  of  stars  of  the  same  temperature  and 
constitution  leads  logically  to  the  conclusion  that  while 
those  stars  having  thick  hydrogen  lines  and  thin  metallic 
lines  are  decreasing  in  temperature  others  in  which  the  rel- 
ative intensities  of  the  lines  are  reversed  are  on  the  con- 
trary increasing  in  temperature. 

In  other  words,  while  some  of  the  stars  are  growing 
cooler  and  more  complex,  and  are  undergoing  an  evolution, 
others  are  growing  hotter  and  less  complex  and  are  under- 


INORGANIC   DEVOLUTION. 


219 


220  THE   NEW   KNOWLEDGE. 

going  a  devolution.  Lockyer  has  found  himself  able  to 
construct  a  table  similar  to,  and  numbered  like,  that  of  the 
stellar  thermometer,  page  209,  in  which  the  stars  are 
placed  in  the  order  of  their  intensity  of  temperature,  and  in 
which  every  star  is  growing  hotter.  We  present  this 
table  of  stars  together  with  the  elemental  substances  com- 
posing them. 

1.  Antares. 

Predominant. — Flutings  of  manganese. 
Fainter. —          Arc  lines  of  metallic  elements. 

2.  Aldebaran. 

Predominant. — Proto-calcium,  arc  lines  of  iron,  calcium  and 

manganese,  proto-strontium,  hydrogen. 
Fainter. —          Proto-iron,  proto-ti/tanium. 

3.  Polaris.  ' 

Predominant. — Proto-calcium,  proto-titanium,  hydrogen, 
proto-magnesium,  proto-iron,  and  arc 
lines  of  calcium,  iron  and  manganese. 

Fainter. —  The  other  proto-metals  and  metals  occur- 
ring in  the  Sirian  genus. 

4.  (        ). 

5.  alpha-Cygni. 

Predominant. — Hydrogen,  proto-calcium,  proto-magnesium, 
proto-iron,  silicon,  proto-titanium,  proto- 
copper,  proto-chromium. 

Fainter.—  Proto-nickel,  proto-vanadium,  proto-manga- 
nese,  proto-strontium,  iron. 

6.  Rigel. 

Predominant. — Hydrogen,  proto-calcium,  proto-magnesium, 

helium,  silicon. 
Fainter. —          Asterium,     proto-iron,    nitrogen,    carbon, 

proto-titanium. 


INOH^ANIODEVOLUTION.  221 

7.  zeta-Tauri. 

Predominant. — Hydrogen,  helium,  proto-magnesium,  aster- 

ium. 
Fainter. —          Proto-calcium,     silicon,    nitrogen,    carbon, 

oxygen,  proto-iron,  proto-titanium. 

8.  beta-Crucis. 

Predominant. — Hydrogen,  helium,  asterium,  oxygen,  nitro- 
gen, carbon. 

Fainter. —  Proto-magnesium,  proto-calcium,  proto-sili- 
con,  unknown,  silicon. 

9.  Alnitam. 

Predominant. — Hydrogen,  helium,  proto-silicon,  unknown 
substance. 

Fainter. —  Asterium,  proto-hydrogen,  proto-magne- 
sium, proto-calcium,  oxygen,  nitrogen, 
carbon. 

10.  Argo. 

Predominant. — Hydrogen  and  proto-hydrogen. 
Fainter. —          Helium,  unknown  substance,  proto-magne- 
sium, proto-calcium,  asterium. 

A  comparison  will  show  that  Group  1  of  this  table  cor- 
responds in  chemical  constitution  with  Group  10  of  the 
other,  Group  6  with  Group  5,  Group  8  with  Group  3.  The 
bottom  of  this  stellar  table  is  the  top  of  the  other.  The 
hottest  stars  of  the  Argonian  type  are  the  culminating  point 
of  a  star's  growth  in  temperature  and  simplicity.  They  are 
also  the  point  of  departure  in  the  star's  decay  in  tem- 
perature and  growth  in  complexity.  The  course  of  a  star's 
history  is  a  curve. 

\Vo  thus  see  that  the  magnificent  inorganic  evolution 
which  we  described  in  the  foregoing  chapter  is  by  no  means 
the  final  expression  of  the  working  of  the  universe.  It  is 


222  THE  NEW  KNOWLEDGE. 

but  the  last  phase,  the  fall  of  the  ascended  rocket  and  its 
bursting  into  the  pyrotechnics  of  our  chemical  elements. 
Taking  some  one  star  as  typical  of  all,  we  may  trace  its 
history  in  accordance  with  the  hypothesis  devised  by 
Lockyer.  The  history  of  a  star  begins  with  a  nebula.  A 
nebula  is  a  vast  swarm  of  meteorites  colliding  together. 
The  meteorites  are  cold  lumps  of  matter  containing  the 
chemical  elements  as  we  know  them  on  earth.  These 
meteorites  in  accordance  with  their  gravitational  attraction 
seek  the  centre  of  the  swarm,  collisions  result,  heat  is 
evolved,  and  the  temperature  gradually  rises. 

Owing  to  the  meteoritic  bombardment,  the  condensing 
and  colliding  mass  becomes  first  so  hot  that  the  low-tem- 
perature arc  lines  begin  to  appear  in  the  spectrum  of  the 
mass  and  we  have  such  a  star  as  Antares  in  Group  1  of  the 
table  above.  But  the  bombardment  and  condensation 
continues,  and  the  temperature  increases  to  such  a  point 
that  the  arc  lines  now  begin  to  disappear  and  the  enhanced 
lines  of  dissociated  elements  begin  to  take  their  place. 
The  star  thus  passes  progressively  through  the  conditions 
exemplified  in  Groups  2,  3,  4  and  5.  Next,  many  of  the 
proto-elements,  themselves,  disappear  and  others,  fewer  in 
number,  take  their  place;  proto-nickel,  proto-manganese, 
proto-vanadium,  pass  away  and  elements  like  proto-mag- 
nesium,  silicon,  oxygen  take  their  place.  Finally,  these  ele- 
ments themselves  disappear  and  the  star  eventually  arrives 
at  the  condition  shown  in  Group  10  in  the  naked  simplicity 
of  nothing  but  hydrogen  and  dissociated  hydrogen  together 
with  small  quantities  of  helium,  proto-magnesium,  proto- 
calcium  and  asterium. 

It  is  now  completely  converted  into  an  incandescent  gas 
at  the  highest  attainable  temperature.  The  progressive  de- 
composition into  simplicity  ceases  for  want  of  meteorites  to 


INORGANIC   DEVOLUTION. 


223 


continue  the  bombardment  and  the  future  history  of  the 
incandescent  gas  is  that  of  a  cooling  body. 

Step  by  step  it  passes  back  through  the  various  groups 
as  in  the  table,  page  209,  ever  decreasing  in  temperature  and 
increasing  in  complexity,  until  it  arrives  at  Group  10,  into 


224  THE   NEW  KNOWLEDGE. 

the  condition  of  our  own  sun  and  Arcturus  in  the  full  pos- 
session of  most  of  the  elements  we  find  on  earth,  and,  even- 
tually, into  the  condition  of  a  dark  star,  extinct  and  dead, 
like  our  earth  itself.  This  progress  of  a  nebulous  swarm  of 
meteorites  to  a  dark  star,  is  illustrated,  diagrammatically,  by 
Lockyer  in  the  accompanying  temperature  curve.  Fig.  54. 
But  the  interesting  question  yet  remains.  Is  this  curve  of 
ascent  and  descent,  which  is  deemed  to  be  common  to  every 
star  in  the  universe,  open  or  closed  ?  What  is  the  relation 
between  the  dark  stars  at  the  end  of  the  process  and  the 
meteorites  at  the  beginning.  If  the  swarms  of  complex  me- 
teorites pass  up  into  the  simplicity  of  the  hottest  stars  and 
back  again  to  the  complexity  of  the  dark  stars  and  common 
earth,  do  the  dark  stars  become  meteorites  again  and  con- 
tinue the  process  infinitely  in  a  circle  of  change,  or,  to  re- 
vert to  the  question  at  the  head  of  the  chapter,  is  the  uni- 
verse a  clock  running  down  ?  We  see,  at  any  rate,  evidence 
of  a  regenerating  influence  at  work,  and  that  if  we  have  an 
inorganic  evolution  we  also  have  an  inorganic  devolution, 
but  in  the  light  of  this  present  chapter  that  is  all  that  can 
be  said.  We  shall  discuss  this  question  from  a  totally  dif- 
ferent point  of  view  in  Chapter  III  Part  VII. 


PART  VII. 


THE  NEW  KNOWLEDGE  AND  OLD  PROBLEMS. 


PART  VII. 
THE  NEW  KNOWLEDGE  AND  OLD  PROBLEMS. 


CHAPTER   I. 

COSMICAL  PROBLEMS  AND  RADIO-ACTIVITY. 

THE  Sux's  HEAT. 

How  docs  the  sun  maintain  its  heat?  This  has  always 
been  a  problem  of  intense  interest  to  the  human  mind.  It 
was  at  first  supposed,  naively,  that  the  sun's  heat  was 
maintained  by  ordinary  chemical  combustion;  that  the  sun 
was  a  burning  fire,  and  that  when  the  coal,  or  what  not,  of 
which  the  sun  was  composed,  was  consumed,  there  would  be 
an  end  of  light  and  heat  and  life.  This  belief  was  shown  to 
be  untenable,  among  others  by  Professor  Tait  who  said: 
"Take  (in  mass  equal  to  the  sun's  mass)  the  most  energetic 
chemicals  known  to  us  and  the  proper  proportion  for  giv- 
ing the  greatest  amount  of  heat  by  actual  chemical  combi- 
nation and,  so  far  as  we  yet  know  their  properties,  we  can- 
not see  the  means  of  supplying  the  sun's  present  waste 
for  even  5,090  years.  ...  It  is  quite  obvious  that  the 
heat  of  the  sun  cannot  possibly  be  supplied  by  any  chem- 
ical process  of  which  we  have  the  slightest  conception. 
.  .  .  This  question  is  quite  unanswerable,  unless  there  be 
chemical  agencies  at  work  in  the  sun  of  a  far  more  powerful 
order  than  anything  we  meet  with  on  the  earth's  surface." 

(227) 


228  THE   NEW  KNOWLEDGE. 

Next,  it  was  supposed  that  the  meteorites  falling  into  the 
sun  could  generate  heat  sufficient  to  maintain  its  energy. 
This  also  was  disproved.  Finally  then  came  Helmholtz's 
theory,  based  upon  the  nebular  hypothesis,  that  the  heat 
of  the  sun  might  be  maintained  by  its  own  contraction 
from  a  nebular  condition.  It  is  not  too  much  to  say  that 
in  recent  years  this  has  been  the  accepted  theory  of  science. 
It  has  always  been  burdened,  however,  by  the  fact  that,  on 
this  basis,  the  sun  could  not  have  maintained  its  energy  and 
have  illuminated  the  earth  in  the  past  for  a  time  sufficient 
to  account  for  the  observed  geological  changes.  Professor 
Young  says  in  his  "  General  Astronomy,"  "  No  conclusion  of 
geometry  is  more  certain  than  this  that  the  contraction  of 
the  sun  to  its  present  size,  from  a  diameter  even  many  times 
greater  than  Neptune's  orbit  cannot  have  been  emitting 
heat  at  its  present  rate  for  more  than  18,000,000  years,  if 
its  heat  has  really  been  generated  in  this  manner. 

Finally,  Lord  Kelvin  has  calculated  the  energy  lost  in 
the  concentration  of  the  sun  from  a  condition  of  infinite 
dispersion  with  the  conclusion  that  it  is  "  on  the  whole 
probable  that  the  sun  has  not  illuminated  the  earth  for 
100,000,000  years  and  almost  certain  that  he  has  not  done 
so  for  500,000,000  years.  As  for  the  future  we  may  say 
with  equal  certainty  that  inhabitants  of  the  earth  cannot 
continue  to  enjoy  the  light  and  heat  essential  to  their  life 
for  many  million  years  longer,  unless  sources  now  unknown 
to  us  are  prepared  in  the  great  store-houses  of  creation." 

We  shall  see  that  in  radio-activity  we  have,  probably, 
an  additional  store  of  energy.  We  know  that  there  exists 
in  the  sun  enormous  quantities  of  the  element  helium.  We 
know,  also,  that  helium  is  a  decomposition  product  from 
radio-active  substances, — and  finally  we  know  that  radio- 
active substances  generate  enormous  quantities  of  heat.  It 


COSMICAL  PROBLEMS   AND  RADIO-ACTIVITY.  229 

is,  therefore,  possible,  and  even  likely,  that  there  exists  in 
the  sun's  mass  large  quantities  of  radio-active  matter,  and 
on  this  supposition  it  is  easily  possible  to  increase  to  an 
enormous  extent  the  duration  of  the  sun's  age  and  heat 
in  the  past,  and  its  maintenance  for  untold  millions  of  years 
in  the  future. 

It  may  be  shown  that  the  presence  of  3.6  grams  of  ra- 
dium in  each  cubic  metre  of  the  sun's  mass  is  sufficient  to 
account  for  its  present  rate  of  emission  of  energy,  or,  cal- 
culated in  another  way,  that  2.5  parts  by  weight  of  radio- 
active matter  in  a  million  would  keep  the  sun  going. 
Rutherford  concludes  that  if  the  energy  resident  in  the 
atoms  of  the  elements  is  available  in  the  sun  that  the  time 
during  which  the  sun  may  continue  to  radiate  at  its  present 
rate  may  be  as  much  as  500  times  longer  than  the  maximum 
limit  afforded  by  Lord  Kelvin. 

We  see  thus  that  the  depressing  conclusion  of  the  older 
science  that  the  earth  must  come  to  an  end  in  a  time 
short  in  comparison  with  its  past  duration,  was  unwarranted. 
It  may,  however,  be  objected  to  this  conclusion  that  if  the 
sun  possesses  radio-activity,  this  radio-activity  ought  to  be 
perceptible  on  earth.  But  this  is  not  so,  for  even  the  most 
penetrating  rays,  the  gramma-rays,  would  be  practically 
stopped  and  absorbed  by  the  earth's  atmosphere  which  is 
equivalent  to  30  inches  of  mercury. 

THE    AGE    OF   THE    EARTH. 

For  the  last  fifty  years  the  age  of  the  earth  as  a  habit- 
able planet  has  been  a  subject  of  bitter  debate  between  the 
physicists  on  the  one  hand  and  the  biologists  and  geolo- 
gists on  the  other.  The  physicists  would  not  grant  the 
time  demanded  by  the  geologists  and  biologists ;  for  whereas 
the  physicists  would  grant  ten  million  years,  the  geologists 


230  THE  NEW  KNOWLEDGE. 

refused  to  be  content  with  less  than  a  thousand  million. 
The  claims  of  each  party  to  the  controversy  seemed  to  be 
irrefragable  and  yet  irreconcilable.  As  an  example  of  the 
physical  method  of  calculation  we  may  cite  the  method  of 
Lord  Kelvin  who  deduced  the  age  of  the  earth  by  a  con- 
sideration of  the  interior  heat  of  the  earth  and  the  rise  of 
temperature  as  one  descends  beneath  the  surface. 

This  rise  in  temperature  amounts  to  about  one  degree, 
Centigrade,  for  every  one  hundred  feet  of  descent,  and  tak- 
ing the  average  heat  conductivity  of  the  earth  as  .004 
(C.  G.  S.  Units)  this  leads  to  the  conclusion  that  ten  million 
years  ago  the  surface  of  the  earth  was  still  molten, — a  con- 
clusion absolutely  unacceptable  to  the  natural  scientists. 
This  conclusion  of  the  physicists  rests  on  a  certain  assump- 
tion which,  however,  at  the  time,  seemed  no  assumption  at 
all.  In  a  word  they  assumed  that  the  earth  was  a  self-cool- 
ing body ;  they  did  not  imagine  that  it  was  a  self-heating  one 
as  well.  We  shall  see  that  as  a  matter  of  fact  the  earth  is 
self-heating. 

One  gram  of  radium  yields  about  100  calories  of  heat  per 
hour,  or  864,000  gram-calories  per  year.  Consequently,  the 
presence  of  2.6  X  10 -13  of  radium  per  unit  volume  or 
4.6  X  10 -14  per  unit  mass  would  compensate  for  the  heat 
which  the  earth  loses  by  conduction.  Or,  taking  the  case  of 
uranium,  which  probably  does  not  evolve  more  that  a  mil- 
lionth of  the  heat  of  radium,  it  may  be  shown  that  the  pres- 
ence of  a  very  small  fraction  of  this  substance  scattered 
throughout  the  earth  would  be  sufficient  not  only  to  keep 
the  earth's  temperature  constant  but  actually  to  raise  it 
from  a  cold  condition  to  a  hot  one.  But  do  we  actually  find 
in  the  ordinary  earth  a  radio-activity  adequate  to  furnish 
heat  sufficient  to  balance  the  earth's  loss  by  conduct  inn? 
We  certainly  do.  We  have  shown,  pages  133  et  seq.,  that  all 


COSMICAL   PROBLEMS   AND   RADIO-ACTIVITY.  231 

matter  is  radio-active,  including  the  soil,  water,  air,  and  in- 
deed practically  all  earthly  substances.  It  has  been  convin- 
cingly shown  by  Rutherford  that  this  radio-activity  of  ordi- 
nary substances  is  in  the  right  order  of  magnitude  to  balance 
the  loss  of  the  earth's  heat  into  space.  It  seems,  then,  that 
the  physicists  were  right  only  so  far  as  they  went,  the  trouble 
being  that  they  did  not  take  into  account  the  possibility  of 
the  earth  being  a  self-heating  body.  The  geologists  and 
biologists  were  also  right — and  they  may  have  the  thousand 
million  years  for  the  earth  as  a  habitable  planet,  if  they 
desire  it. 


CHAPTER  II. 

THE  MECHANICAL  PRESSURE  OF  LIGHT  AND   ITS 
CONSEQUENCES. 

To  the  reader  who  has  not  followed,  particularly,  the 
course  of  scientific  advance  during  the  last  ten  years,  the 
heading  of  this  chapter  must  seem  upsetting  to  all  accepted 
notions  as  to  the  nature  of  light.  By  light  is  meant  un- 
dulations in  the  omnipresent  ether  and  it  seems  odd  to 
attribute  mechanical  pressure  to  such  an  immaterial  thing. 
Yet  in  1873  Clerk-Maxwell,  in  one  of  his  prescient  mathe- 
matical inspirations  showed  that  such  a  pressure  should 
exist,  and  his  conclusion  was  mathematically  borne  out  in 
1876  by  Bartoli  on  totally  different  grounds.  Briefly  it 
may  be  stated  that  this  light  pressure  p  is  determined  if 
we  know  the  amount  of  energy  E  in  the  light,  the  reflect- 
ing power  of  the  substance  that  receives  it  r,  and  v  the 
velocity  of  light,  for  then 

P-f  (1  X  r) 

The  experimental  verification,  as  is  often  the  case,  lagged 
long  behind  the  mathematical  prediction.  In  1901,  how- 
ever, Peter  Lebedew  actually  proved  and  measured  the 
mechanical  pressure  of  light.  The  pressure  discovered  was 
small,  but  the  smallness  of  a  thing  is  often  an  inverse 
measure  of  its  importance,  and  as  this  light  pressure  has 
been  found  adequate  to  the  task  of  explaining  some  of 
earth's  greatest  mysteries  we  shall  indicate  his  method 
here.  Briefly,  he  allowed  a  beam  of  light  to  fall  on  a  sus- 
(232) 


MECHANICAL   PRESSURE   OF  LIGHT;   ITS   CONSEQUENCES.    233 

pended  disc  in  a  bulb  containing  a  vacuum.  This  vacuum 
was  attained  with  the  greatest  care  by  first  exhausting  the 
bulb  to  the  highest  degree  possible  and  then  freezing  out 
the  residue  of  mercury  vapour.  In  such  a  vacuum  the  disc 
was  repelled  on  the  impact  of  the  light-beam  and  its  repul- 
sion was  measured  by  its  torsional  effect  on  the  suspending 
wire.  This  repulsive  pressure  of  the  light  was  found  very 
nearly  equal  to  that  calculated  so  long  in  advance  by  Clerk- 
Maxwell.  Since  Lebedew's  demonstration,  Nichols  and 
Hull  have  repeated  his  work  with  greater  exactness  and 
there  is  now  no  shadow  of  doubt  as  to  the  fact  that  it  has 
Maxwell's  value.  This  light  pressure  at  the  distance  of  the 
earth  from  the  sun  is  small,  not  quite  a  milligram  per 
square  metre  of  the  earth's  surface,  or,  put  roughly,  70,000 
tons  on  the  whole  earth.  Were  we  to  consider  only  the 
effect  of  the  impact  on  large  bodies  our  interest  would  not 
proceed  very  far,  but  things  take  on  a  different  complexion 
when  we  notice  the  remarkable  effect  of  size  on  the  relation 
between  the  light  pressure  and  weight  or  gravitational 
attraction.  The  light  pressure  is  applied  only  on  the  sur- 
face and  is  proportional  to  the  surface  while  weight  or  the 
pull  of  gravitation,  on  the  other  hand,  affects  the  whole 
body. 

Suppose  we  divided  a  sphere,  such  as  a  cannon  ball,  into 
eight  equal  spheres.  The  sum  of  the  surfaces  of  these  eight 
spheres  would  be  twice  that  of  the  original  sphere  while 
the  weight  of  gravitative  pull  would  remain  the  same.  If 
we  continued  the  process  of  division  until  the  spheres  were 
the  size  of  the  smallest  shot,  the  total  sum  of  their  sur- 
faces would  be  enormous  compared  with  the  original  sphere 
while  the  weight  would  again  be  equal  to  that  of  the  can- 
non ball.  If  we  continued  the  division  on  and  on  we  should 
eventually  come  to  a  body  so  small  that  the  ratio  of  its 


234  THE   NEW   KNOWLEDGE. 

surface  to  its  weight  would  be  enormous, — it  would  be  al- 
most all  surface.  Now  the  greater  the  surface  the  greater 
the  effect  of  the  light  pressure  and  hence  without  going 
down,  by  any  means,  into  infinitesimals  the  process  of  divi- 
sion carries  us  to  a  particle  so  fine  that  the  light  pressure 
will  exactly  balance  its  weight.  This  is  the  case  with  a 
particle  of  earth  1/100,000  of  an  inch  in  diameter.  Such  a 
particle  would  neither  be  attracted  nor  repelled,  from  the 
sun,  for  the  sun's  pull  upon  it  is  exactly  balanced  by  the 
repulsive  force  of  the  sun's  light.  If  the  particle  is  smaller 
still  it  is  repelled  from  the  sun  and,  in  fact,  if  the  particle 
is  exceedingly  small  the  light-push  may  enormously  exceed 
its  weight.  But  1/100,000  of  an  inch  is  not  in  itself  very 
small.  We  know  many  bodies  smaller  than  this,  without 
considering  the  atoms  and  corpuscles  of  preceding  chapters. 

COMETS'  TAILS  AND  THEIR  EXPLANATION. 

One  of  the  greatest  mysteries  in  astronomical  science  has 
been  the  comet's  tail  and  why  it  points  away  from  the  sun. 
The  facts  are  generally  known.  The  tail  of  a  comet  may  be 
any  length  up  to  100,000,000  miles.  It  develops  and  grows 
larger  as  the  comet  approaches  the  sun,  proceeding  back 
from  the  direction  of  motion  of  the  comet  like  the  smoke 
from  a  steamer;  but  unlike  the  steamer-smoke,  as  the  comet 
rounds  the  sun  and  flies  away;  the  tail  now  precedes  the  head. 
It  is  precisely  as  though  there  was  a  strong  repulsive  wind 
blowing  away  from  the  sun  and  sufficing  to  keep  the  comrt  'a 
tail  pointed  away  from  it.  The  nature  of  this  repulsive 
force  has  been  the  mystery  of  astronomy.  Now,  however, 
we  may  consider  ourselves  acquainted  with  its  cause. 

The  whole  comet  has  a  spectrum  practically  identical 
with  that  of  a  bunsen  burner  consuming  ordinary  gas, 
and,  hence,  evidently  consists  of  hydrocarbons.  In  addi- 


MECHANICAL   PRESSURE   OF   LIGHT;   ITS   CONSEQUENCES.    235 

tion,  as  the  head  approaches  the  sun  evidence  of  iron, 
magnesium  and  other  metals  becomes  apparent.  We  can 
easily  see  that  as  the  comet  approaches  the  sun  the  hydro- 
carbons must  break  up  into  hydrogen  gas  and  other  hydro- 
carbons of  higher  boiling  point.  Finally  as  the  sun  is  ap- 
proached and  the  heat  becomes  intense  these  hydrocarbon* 
themselves  will  break  up  into  free  carbon  in  the  form  of 
soot.  The  whole  process  is  analogous  to  that  which  takes 
place  in  an  ordinary  gas  flame  with  the  exception  that 
since  there  is  no  air,  the  soot  formed  cannot  burn  into  gas 
but  must  exist  in  the  form  of  small  particles.  These  small 
particles  whether  in  the  form  of  a  mist  of  liquid  hydro- 
carbons, or  in  the  form  of  a  carbon  soot,  must  fall  under 
the  sway  of  the  mechanical  pressue  of  light.  If  they  are 
so  small  that  the  light-pressure  overbalances  the  forces  of 
the  sun's  gravitative  pull  they  will  be  driven  back  from  the 
comet  with  a  speed  depending  on  their  size  and  will  con- 
stitute the  ordinary  comet's  tail.  If  these  small  particles 
vary  in.  size,  as  would  naturally  be  the  case,  the  rate  at 
which  the  light  drives  them  will  vary  and  the  resulting 
tail  will  be  curved. 

Since  the  material  composing  the  comet  is  hetero- 
geneous, one  constituent  after  another  will  decompose  and 
several  tails  will  be  formed  successively  with  curvatures 
depending  on  the  size  of  the  particles.  If  the  particles  are 
larger  than  can  be  repelled  by  the  sunlight  they  will  form  a 
tail  pointing  towards  the  sun,  which  is  a  rare  phenomenon,  but 
occasionally  observed.  The  sizes  of  the  mist  particles  of  the 
comets'  tails  necessary  to  account  for  their  observed  length 
and  curvature  have  been  calculated,  and  are  quite  in  the 
order  of  particles  we  are  familiar  with  on  earth  in  the  early 
sta^os  of  combustion.  They  vary  in  diameter  from  1/10,000 
to  6/1,000  of  a  millimetre.  Now  a  particle  one-half  the 


236  THE   NEW   KNOWLEDGE. 

"weight"  which  the  sunlight  can  balance,  about  half  the 
thousandth  of  a  millimetre,  would  travel  under  the  pressure 
of  light  more  that  865,000  miles  an  hour.  In  comets'  tails 
we  probably  have  particles  whose  diameter  is  less  than  one- 
eighteenth  of  this.  Such  particles  would  travel  the  same 
distance  in  less  than  four  minutes. 

It  is  not  surprising,  then,  that  "  the  tail  of  the  great  comet 
of  1680  was  found  by  Newton  to  have  been  no  less  than 
20,000,000  leagues  in  length  and  to  have  occupied  only  two 
days  in  its  emission  from  the  comet's  body, — a  decisive 
proof  this  of  its  being  darted  forth  by  some  active  force, 
the  origin  of  which,  to  judge,  by  the  direction  of  the  tail, 
must  be  sought  in  the  sun  itself."  The  whole  matter  is  ac- 
counted for  by  the  mechanical  pressure  of  light, — a  force  in 
the  universe  hitherto  unsuspected. 

THE  SOLAR  PROMINENCES  AND  THE  CORONA. 

In  a  solar  eclipse,  at  the  precise  moment  when  the  moon 
blots  out  the  sun's  disc  there  becomes  visible  around  the 
edge  of  the  sun  a  number  of  magnificent  scarlet  steamers, 
or  clouds,  some  of  them  60,000  miles  in  height  and  held 
suspended  over  the  sun.  These  are  the  solar  "prominences." 

In  addition  to  these  fiery  streams  there  exists  also  a  beauti- 
ful halo  or  " glory"  of  a  greenish  or  pearly  lustre  which 
contrasts  finely  with  the  scarlet  hue  of  the  prominences. 
This  "halo"  has  been  called  the  "corona." 

Both  the  prominences  and  corona  consist  of  matter  in  a 
highly  rarefied  condition  and  the  so-far  unanswered  question 
of  the  astronomers  has  been,  "  How  is  this  matter  held  up?  " 
The  complete  answer  seems  to  be,  "It  is  held  up  by  the 
pressure  of  the  sun's  own  light."  The  sun  must  project 
vapours  into  space.  These  vapours  will  condense  into  drops 
where  they  meet  the  cold  of  outer  space.  These  drops,  if 


MECHANICAL  PRESSURE   OF    LIGHT;    ITS    CONSEQUENCES.    237 

larger  than  the  critical  size,  will  fall  slowly  back  towards 
the  sun  constituting  the  prominences;  if  smaller  than  the 
critical  value,  they  will  be  driven  away  from  the  sun  forming 
the  curious  streams  of  the  corona.  If  they  are,  practically, 
just  the  size  which  the  light  can  support  they  will  float 
permanently  suspended  and  will  constitute  the  main  body 
of  the  corona.  Even  the  mysterious  "  hairy  structure "  of 
the  corona  is  explicable  as  due  to  the  supporting  power  of 
light  on  particles  of  different  sizes. 

THE    ZODIACAL   LIGHT. 

Just  after  twilight  on  any  clear  evening  in  winter  or 
spring  there  may  be  seen  on  the  western  horizon  a  faint 
soft  beam  of  light.  This  beam  seems  to  proceed  out  from 
each  side  of  the  sun  to  some  distance  beyond  the  earth's 
orbit.  It  is  called  the  zodiacal  light.  Its  cause  has  been 
another  of  the  "mysteries"  of  astronomy,  though  it  finds 
an  easy  present-day  explanation  in  terms  of  our  theory. 
It  was  shown,  page  51,  that  incandescent  carbon  and  metals 
gave  off  negatively  electrified  particles  or  corpuscles  a 
thousand  times  smaller  than  the  smallest  atom.  We  know 
that  enormous  quantities  of  carbon  exist  in  the  photosphere 
of  the  sun,  and  exist,  moreover,  at  a  temperature  vastly 
greater  than  any  known  on  earth.  This  carbon  must  emit 
corpuscles,  and,  since  the  corpuscles  are  almost  infinitely 
small,  the  effect  upon  them  of  the  mechanical  pressure  of 
light  must  be  extreme.  The  sun  must,  therefore,  bombard 
all  space  with  corpuscles  travelling  with  an  immense  ve- 
locity. These  corpuscles,  which  it  should  be  remembered  \ 
are  negatively  electrified,  when  they  strike  the  outer  regions  | 
of  the  earth's  atmosphere  will  charge  it  also  negatively,  and 
when  this  charge  reaches  a  certain  value  the  oncoming  rush 
of  corpuscles  will  be  deflected  by  the  similar  electrification 


238  THE   NEW   KNOWLEDGE. 

of  the  atmosphere  so  that  it  will  stream  past  the  earth  on 
each  side  in  a  hyperbolic  orbit.  Far  out  in  space  on  the 
side  away  from  the  sun  they  will  meet  with  other  particles. 
We  have  shown,  page  63,  that  corpuscles  are  remarkable 
in  being  able  to  act  as  nuclei  about  which  other  corpuscles 
and  atoms  and  molecules  will  collect.  When  they  meet, 
therefore,  with  other  particles  back  of  the  earth,  this  con- 
densation will  take  place  and  if  the  particles  formed  are 
greater  than  the  critical  diameter  which  the  pressure  of 
light  can  control  they  will  drift  back  with  increasing  velocity 
past  the  earth  and  towards  the  sun.  If  we  could  take  our 
stand  on  the  moon  we  should  probably  see  the  earth  at- 
tended by  a  faint  double  tail  the  more  conspicuous  one 
pointing  away  from  the  sun  and  a  fainter  one  pointing 
toward  him.  It  is  this  sheaf  of  light  on  each  side  of  the 
earth,  due  to  a  corpuscular  bombardment  from  the  sun, 
which,  in  the  opinion  of  Arrhenius,  is  the  cause  of  the  zodi- 
acal light.  It  should  be  stated  here  that  Arrhenius  is  the 
father  of  nearly  all  this  theoretical  interpretation  of  the  ob- 
served mechanical  pressure  of  light. 

THE  AURORA  BOREALIS. 

The  Aurora  Borealis  has  been  still  another  mystery. 
We  shall  see  that  the  new  knowledge  has  something  to  say 
as  to  its  elucidation.  In  Part  III  it  was  shown  that  the 
Corpuscles  from  red-hot  carbon,  Crookes'  tubes  and  the 
beta-rays  of  radium  are  deflected  by  a  magnet  in  such  a 
way  that  they  describe  helices  around  the  lines  of  magnetic 
force.  If  the  magnetic  field  is  strong  enough  they  may  be 
bent  into  a  complete  circle  inside  a  moderately  large  tube, 
page  57.  If  there  is  such  a  thing  as  the  continuity  of 
natural  law,  the  earth  should  be  bombarded  by  these  cor- 
puscles projected  from  the  sun.  Hut  the  earth  is  a  magnet, 


MECHANICAL   PRESSURE   OF  LIGHT;  ITS   CONSEQUENCES.   239 

and  the  lines  of  force  proceed  from  pole  to  pole.  Now  the 
corpuscles  must  arrive  most  thickly  over  the  equatorial 
region  of  the  earth  where  the  earth  is  directly  exposed  to 
them.  They  must  be  at  once  caught  by  the  lines  of  force 
and  must  travel  along  them  in  winding  helices  ever  coming 
closer  and  closer  and  farther  and  farther  down  into  the 
atmosphere  as  they  approach  the  poles.  At  a  certain  dis- 
tance from  the  poles  they  find  themselves  in  an  atmosphere 
comparable  with  our  high  vacua  and  they  then  begin  to 
give  out  the  shifting  and  darting  lights  of  the  cathode  rays, 
though  this  can  be  only  at  the  cost  of  their  existence  for 
their  energy  is  absorbed  in  causing  the  luminosity.  These 
"  darting  and  shifting  lights  of  the  cathode  rays  "  in  ac- 
cordance with  this  speculation  account  for  the  Aurora 
Borealis  as  well  as  for  "  the  dark  circles  around  the  magnetic 
poles  from  which,  as  from  behind  a  curtain,  the  leaping 
pillars  of  the  Aurora  rise."  If  the  theory  is  true,  there 
should  be  some  connection  between  the  earth's  magnetic 
field  and  the  Aurora  and  since  they  are  both  due  to  solar 
influence  they  should  be  related,  as  well,  to  the  sun's 
activity  as  revealed  in  the  number  of  sun  spots. 

In  fact,  the  Aurora  Borealis,  the  earth's  magnetism  and 
sun  spots  should  all  vary  together.  It  has  long  been  known 
that  they  all  do  vary  together  in  a  very  remarkable  way. 

ATMOSPHERIC    ELECTRICITY. 

Another  peculiarity  possessed  by  corpuscles  travelling 
with  high  velocity  is  their  ability  to  knock  to  pieces  or 
ionize  a  gas  through  which  they  pass,  and  that  these 
ions  act  as  nuclei  of  condensation  of  clouds.  If,  there- 
fore, the  earth  is  bombarded  by  solar  corpuscles  they  should 
ionize  the  air  in  the  upper  regions  and  this  should  result 
in  the  formation  of  clouds.  We  have  here  a  beautiful 


240  THE   NEW   KNOWLEDGE. 

explanation  of  the  hitherto  inexplicable  fact  that  cloud- 
formation  in  the  upper  air  varies  with  the  frequency  of 
auroras. 

METEORITES    AND    NEBULA. 

The  number  of  corpuscles  intercepted  by  the  earth  is 
of  course  infinitesimal  compared  with  those  that  miss  the 
earth  altogether  and  continue  on  through  interstellar  space. 
Through  their  immense  velocity  under  the  pressure  of  light 
we  can  easily  see  how  they  would  overcome  their  electrical 
repulsions,  clash  together,  condense  and  form  the  meteorites 
which  flame  through  the  upper  air  and  occasionally  reach 
the  earth  itself  as  "  thunder-bolts.''  AYe  are  not  even  yet 
at  the  end  of  the  functional  power  of  the  corpuscle.  Many 
of  them  will  escape  these  traps  to  strike  the  nebulae  and 
comets.  The  fact  that  both  nebula)  and  comets  are  cold 
bodies  and  yet  shine  with  their  own  light  has  always  been 
a  perplexing  matter.  It  need  be  so  no  longer,  for  on  the 
impact  of  a  rain  of  corpuscles  the  tenuous  gaseous  mass  of 
a  nebula  or  a  comet's  tail  would  of  very  necessity  shine 
with  the  same  light  that  we  see  in  the  Aurora  or  a  Crookes' 
tube  on  earth. 

It  is  a  highly  interesting  and  significant  fact  that  these 
corpuscles  found  in  candle  flames,  hot  metals,  Crookes' 
tubes  and  radium,  which  apparently  constitute  the  very 
essence  of  matter  and  electricity,  should  also  serve  to  ex- 
plain, reasonably  and  adequately,  some  of  the  most  per- 
plexing phenomena  in  the  whole  range  of  natural  knowledge. 


CHAPTER  III. 

Ox  THE  RECONSTRUCTION  OF  A  UNIVERSE. 

It  is  now  possible  to  renew  the  discussion  postponed  from 
page  224  as  to  whether  or  not  the  universe  is  losing  its  avail- 
able energy  and  is  going  steadily  to  a  condition  of  rest  and 
extinction;  whether  or  not  the  universe  is  a  clock  running 
down.  Only  yesterday,  practically,  the  affirmative  side  of 
this  question  seemed  to  be  one  of  the  safest  and  surest  con- 
clusions of  modern  science.  But  we  have  seen  more  than  one 
of  these  long-accepted  generalizations  seriously  impugned 
and  it  may  be  that,  in  the  light  of  this  new  knowledge,  we 
shall  find  that  this  widely  accepted  dictum  of  science,  that 
the  universe  is  proceeding  fatally  to  the  extinction  of  its 
available  energy,  is  also  a  legitimate  matter  of  deliberate 
question. 

The  reasons  for  this  current  conception  have  seemed,  until 
recently,  irrefragable.  In  the  words  of  Mr.  A.  Daniell,  "In 
every  Transformation  of  Energy  we  find  that  some  Energy 
is  wasted  through  conversion  into  Heat,  the  result,  direct  or 
indirect,  of  friction,  noise,  flashes  of  light,  and  so  on.  This 
heat  is  presently  distributed  pretty  uniformly  among  its 
surrounding  objects,  and  can  no  more  be  made  use  of  by 
us  for  the  sake  of  producing  work.  A  large  quantity  of  the 
Energy  of  the  Universe  must  have  already  assumed  this 
relatively  useless  condition,  and  in  the  course  of  time  the 
whole  of  the  Energy  in  the  Universe  will  have  assumed  it. 
The  Energy  of  the  Universe  is  a  constant  amount,  some  of 
16  (241) 


242  THE   NEW   KNOWLEDGE. 

it  is  available,  some  is  non-available:  the  former  is  in  every 
phenomenon  somewhat  diminished  but  never  increased :  the 
non-available  energy  is  constantly  increasing:  hence  the 
Available  Energy  of  the  Universe  tends  to  Zero."  Again, 
Professors  Stewart  and  Tait  say:  ".  .  .  it  is  absolutely 
certain  that  age  after  age  the  possibility  of  such  trans- 
formations (of  energy)  is  becoming  less  and  less;  and,  so 
far  as  we  yet  know,  the  final  state  of  the  present  Universe 
must  be  an  aggregation  into  one  mass  of  all  the  matter  it 
contains,  i.  e.,  the  potential  energy  gone,  and  a  practically 
useless  state  of  kinetic  energy,  i.  e.,  uniform  temperature 
throughout  that  mass." 

Is  such  a  conclusion  absolutely  certain?  It  all  depends 
upon  the  validity  of  the  Second  Law  of  Thermodynamics. 
This  "law"  states  that  "one  part  of  a  body  of  uniform 
temperature  cannot  grow  hotter  at  the  expense  of  the  heat 
of  the  remainder  unless  work  is  performed  upon  it,"  con- 
sequently, if  the  energy  of  the  universe  is  being  continu- 
ously degraded  into  heat  of  equal  temperature  it  will  even- 
tually be  a  dead  universe.  That  this  "law"  however  has 
limitations  has  been  recognised  since  the  time  of  Clerk- 
Maxwell.  The  kinetic  theory  of  gases  teaches  us  that  in  a 
gas  of  uniform  temperature,  while  the  average  velocity  of 
the  molecules  comprising  the  gas  must  be  a  constant  quan- 
tity the  individual  velocities  of  the  molecules  must  vary  to 
a  great  degree,  some  of  them  possessing  velocities  higher  and 
others  lower  than  the  average. 

Clerk-Maxwell  imagined  a  firm  partition,  full  of  little 
doors,  to  be  placed  so  as  to  divide  the  vessel  into  two, 
and  to  each  door  he  placed  an  intelligent  little  demon 
with  precise  instructions  to  open  the  door  whenever  he 
saw  a  quick  moving  molecule  approach  in  such  a  way 
that  it  could  get  through  from  the  first  compartment 


OX   THE   RECONSTRUCTION   OF   A   UNIVERSE.  243 

into  the  second,  and  whenever  he  saw,  also,  that  he  could 
allow  a  slow-moving  molecule  to  escape  from  the  second 
compartment  into  the  first.  It  is  obvious  that  the  demon 
would  eventually  succeed  in  dividing  the  molecules  of  the 
gas  into  two  groups,  one  group  of  which  would  possess 
greater  kinetic  energy  than  the  other  and  would  be  capable1 
of  doing  work,  say,  in  moving  the  dividing  partition,  and  all 
this  without  the  performance  of  work  upon  it.  The  second 
law  would  thus  be  contravened.  The  only  reason  that  this 
contravention  of  the  "law"  is  not  possible  in  a  practical 
sense  is  the  exceedingly  small  size  of  the  gaseous  molecules 
and  their  immense  number. 

The  great  question  for  us  is  this:  Is  the  "law"  which 
we  see  has  its  limitations  in  the  case  of  gases  also  limited 
in  the  case  of  sub-atomic  change?  Throughout  this  book 
we  have  had  evidence,  and,  in  fact,  demonstrations,  of  the 
continuous  disintegration  of  the  heavy  atoms  into  sub- 
atoms.  The  heavy  elements  of  matter  are  undergoing  a 
steady  and  inevitable  decomposition  with  the  continuous 
production  of  inter-elemental  energy.  Now,  if  the  lighter 
elements  were  at  the  same  time  undergoing  the  reverse 
process,  were,  in  fact,  synthesizing  themselves  into  the 
heavy  elements  with  the  absorption  of  energy  so  that  as 
much  energy  was  collected  up  by  them  in  their  growth  as 
was  "wasted"  by  the  decomposition  of  the  heavy  elements 
in  their  decay,  the  universe  of  matter  would  keep  its  avail- 
able energy  constant;  it  would  constitute  a  conservative 
system  having  neither  beginning  nor  end.  It  is  true  that 
the  energy  evolved  in  atomic  disintegration  is  enormous  in 
amount,  page  176,  and  that  the  energy  absorbed  in  atomic 
synthesis  must  be  equal  to  it ;  but  that  does  not  constitute  a 
valid  reason  why  our  atoms,  which  we  consider  to  be  aggre- 
gations of  corpuscles,  should  not  continuously  grow  by  the 


244  THE   NEW  KNOWLEDGE. 

gradual  accretion  of  other  corpuscles  and  the  storage  of  the 
requisite  energy  through  vast  stretches  of  time.  An  objection 
has  been  urged  against  the  possibility  of  the  growth  of  atoms 
on  the  ground  that  if  the  lightest  atoms  gradually  grew  into 
the  heaviest  there  should  be  an  infinite  number  of  transition- 
forms  from  hydrogen  to  uranium,  and  we  find,  on  the  con- 
trary, that  the  70  odd  elements  are  sharply  defined.  This 
objection,  however,  does  not  hold  good.  While  it  is  not 
necessary  to  assume  that  intermediate  elemental  forms  may 
not  exist  to  some  extent,  their  amount  would  be  insignificant. 
The  atoms  of  the  periodic  table  on  the  basis  of  Thomson's 
theory  are  aggregations  of  corpuscles  representing  collections 
of  maximum  stability,  and,  hence,  a  transition  collection 
would  hasten  to  these  points,  and  we  should  neither  find 
them  existing  in  notable  quantity  or  be  able  to  conserve 
them  any  more  than  we  can  conserve  the  transition  products 
of  atomic  disintegration  like  thorium  X  or  the  emana- 
tion X  of  radium.  There  is,  therefore,  no  known  impossi- 
bility inherent  in  the  conception  of  a  conservative  universe, 
[ave  we  any  positive  reason  for  believing  in  it?  It  must  be 
confessed,  at  the  present  time,  not  much.  In  Chapter  III, 
Part  VI,  we  discovered  that  there  is,  apparently,  a  regenerat- 
ing influence  at  work  in  the  stars  by  which  the  cold  complex 
nebulae  of  meteorites  become  converted  gradually  into  the 
hottest  stars  of  simple  chemical  constitution  whence  they 
again  fall  into  coldness  and  complexity;  and,  very  recently, 
Sir  William  Ramsay  announced  that  he  believes  himself  to 
have  synthesized  one  element  into  another;  but  this  is  all, 
and  it  does  not  suffice  by  any  means  to  prove  that  the 
universe  of  matter  is  building  up  its  available  energy  as 
fast  as  it  dissipates  it. 

The  hypothesis  of    the   reconstruction  of  the  universe 
of  matter  is  therefore,  at  the  present  time,  a  pure  specula- 


ON   THE   RECONSTRUCTION    OF   A   UNIVERSE.  245 

tion  but  it  is  a  speculation  which  may  be,  as  Mr.  Soddy 
says,  "one  of  those  coming  events  which  cast  their  shadows 
before."  It  is  discussed  here  because  of  its  extreme  im- 
portance. If  the  universe  is  running  down  its  available 
energy  into  uselessness,  there  must  have  been  a  precise 
moment  of  time,  however  far  back  we  may  place  it,  when 
the  energy  was  all  available  and  when  it  was  initiated 
in  a  sudden  beginning  by  a  single  creative  act.  Conse- 
quently, there  must  have  been  a  time  behind  which  our 
present  laws  did  not  operate.  Also,  there  must  be  a  time  in 
the  future  when  the  universe  will  have  grown  to  a  definite 
exhaustion  and  death.  The  death  will  come  gradually  but 
the  beginning  must  have  been  sudden  and  due  to  a  creative 
act. 

If  on  the  contrary,  the  waste  of  energy  is  replaced  by 
growth,  the  universe  is  immortal  or  eternal  both  in  the 
future  and  in  the  past.  If  the  old  conception  is  true,  it  is 
necessary  to  say,  "God  made  it  and  started  it  at  a  definite 
time  to  run  its  course."  If  the  second  conception  is  true, 
we  may  say:  "The  Universe  is  God  in  one  phase  of  Him  and 
it  possesses  His  attribute  of  eternal  duration."  This,  to  most 
people  of  scientific  training,  is  the  more  acceptable  conclu- 
sion. The  solution  of  this  great  problem  seems  now,  at  any 
rate,  a  legitimate  aspiration  of  science  and,  for  the  present, 
if  the  new  knowledge  has  not  proved  positively  that  the 
past  and  future  of  the  universe  is  infinite,  it  has,  beyond  all 
question,  enormously  increased  its  boundary  in  time. 


CHAPTER  IV. 
THE  DEFINITIONS  OF  SCIENCE  RE-DEFINED. 

The  summation  of  what  the  new  philosophy  has  to  say 
with  regard  to  the  older  science  is  best  expressed,  synopti- 
cally,  in  the  form  of  tentative  and  supplementary  definitions. 
These  "definitions"  will  be  enunciated  in  the  order  of  their 
simplicity  so  that  they  may  afford  a  concise  synthesis  of 
the  views  of  the  new  philosophy  in  their  relation  to  the  great 
fundamental  problems  of  the  universe.  It  is  understood 
that  the  new  philosophy  is  very  new,  and  that  its  definitions 
are  wholly  provisional.  They  represent  the  author's  inter- 
pretation of  the  teaching  of  radio-activity  as  he  has  gleaned 
it  from  a  worker  here  and  a  worker  there.  The  "  defini- 
tions" are  virtually  "propositions"  to  stand  or  fall  as  they 
may. 

Electricity: 

Positive  Electricity: 

What  positive  electricity  is,  nobody  knows;  unless  the 
statement  that  it  is  a  mode  of  manifestation  of  the  all- 
pervading  ether  constitutes  knowledge,  though  even  this  we 
do  not  certainly  know.  It  has  either  no  mass,  or  very  little. 
It  seems  to  exist  in  the  form  of  particles  the  size  of  atoms. 
In  fact,  the  size  of  the  atom  seems  to  determine  the  size  of 
the  positive  electricity  connected  with  it.  Positive  elec- 
tricity is  never  obtained  free  from  atoms. 

Negative  electricity:  Page  185. 

Negative  electricity  is  partir-ulate  in  character;  that  is,  it 
(246) 


THE    DEFINITIONS   OF   SCIENCE   RE-DEFINED.  247 

consists  of  separate  definite  units.  These  units,  if  they 
could  be  obtained  in  a  state  of  rest,  would,  it  is  deemed, 
have  no  mass  whatever.  Whether,  under  these  conditions 
they  would  have  spatial  dimension  is  not  known. 

Mass:  Page  184. 

A  unit  of  negative  electricity  in  motion  carries  along  or 
drags  with  it  a  portion  of  the  surrounding  ether.  This 
"bound"  ether  carried  by  the  moving  negative  unit  is  what 
we  call  mass.  The  mass  of  all  matter  is  believed  to  be  due 
solely  to  the  amount  of  ether  dragged  along  by  the  moving 
electrical  units. 

Corpuscle:  Pages  65  and  184. 

A  moving  unit  of  negative  electricity  together  with  its 
bound  ether  is  a  corpuscle.  The  mass  of  a  corpuscle  de- 
pends upon  the  amount  of  bound  ether  connected  with  the 
moving  unit  and  this  depends  on  the  velocity.  The  average 
mass  of  a  corpuscle  is  about  one  one-thousandth  of  that  of  a 
hydrogen  atom.  Corpuscles  may  exist  free  from  matter. 

Atom:  Pages  10  and  171. 

A  congeries  of  corpuscles  surrounded  and  balanced  by  a 
sphere  of  positive  electricity  is  an  atom.  The  weight  of  the 
atom  is  due  to  the  weight  of  the  constituent  corpuscles,  and 
the  properties  of  the  atom  are  due  to  their  number  and  ar- 
rangement. Since  it  takes  a  large  number  of  corpuscles  to 
constitute  an  atom  its  structure  is  thus  extremely  complex. 

Chemical  Union:  Page  167. 

Certain  corpuscular  aggregations  will  hold  in  an  unstable 
condition  a  few  more  corpuscles  than  exactly  suffices  to  bal- 
ance the  surrounding  sphere  of  positive  electricity.  The 
atom  consisting  of  them  is  thus  as  a  whole  negatively 
electrified.  Other  arrangements  will  hold  a  few  less  cor- 
puscles than  suffices  to  balance  the  positive  electricity. 
This  leaves  the  atom  positively  electrified.  If  these  two 


248  THE    NEW   KNOWLEDGE. 

types  of  atoms  are  free  to  move  they  unite  together  and 
neutralize  each  other  electrically.  This  union  is  chemical 
union.  Chemical  union  is  thus  nothing  but  electrical  union. 
Chemical  valency  is  simply  a  measure  of  the  corpuscles  more, 
or  the  corpuscles  less,  than  the  atom  will  hold  in  a  stable 
condition. 

Molecule:  Pages  9  and  167. 

A  group  of  atoms  united  together  electrically  constitutes 
a  molecule. 

Matter:  Pages  2  and  184. 

Any  mass  of  matter  is  x  molecules,  a  molecule  is  y  atoms, 
an  atom  is  z  corpuscles  surrounded  by  positive  electricity 
and  a  corpuscle  comprises  a  unit  of  negative  electricity. 
Matter  is  thus  explained  away  as  being  electricity  and  noth- 
ing but  electricity. 

Radio-activity:  Page  169. 

Certain  vast  assemblages  of  corpuscles  comprising  the 
heaviest  atoms  are  somewhat  unstable.  As  their  kinetic 
energy  decreases  the  aggregation  ''explodes"  and  the  cor- 
puscles re-arrange  themselves  with  the  evolution  of  energy 
and  the  projection  of  some  of  the  products  of  the  re-arrange- 
ment. This  is  radio-activity. 

The  alpha-rays  from  a  radio-active  body  are  simplified 
arrangements  of  corpuscles  resulting  from  the  explosion. 
They  are  positively  electrified  sub-atoms. 

The  beta-rays  are  free  corpuscles  let  loose  from  the  ex- 
plosion. 

The  gamma-rays  are  probably  identical  in  nature  with 
X-rays  and  are  probably  pulses  in  the  ether  set  up  by  the 
explosion. 

Inertia:  Page  179. 

The  only  inertia  known  is  the  inertia  of  the  "bound" 
ether  carried  along  by  the  moving  negative  electrical  units. 


THE    DEFINITIONS   OF   SCIENCE   RE-DEFINED.  249 

The  inertia  of  any  mass  of  matter  is  thus  electrical  inertia. 

Current  Electricity:  Page  186. 

An  electrical  current  is  nothing  but  a  series  of  corpuscles 
''handed  along"  from  one  atom  to  another  through  the  wire. 
At  the  beginning  of  their  course  there  is  a  deficiency  of 
corpuscles  and  the  positive  electricity  of  the  atoms  thus 
appears.  At  the  end  there  is  a  gain  in  corpuscles  and  the 
negative  electricity  is  manifested. 

Electrical  Self-induction:  Page  181. 

The  tendency  of  corpuscles  to  maintain  their  state  of 
motion  which  we  know  in  matter  as  inertia  is  the  same 
tendency  expressed  as  they  are  handed  on  through  a  wire 
or  in  the  oscillations  of  an  electric  spark.  Electrical  self- 
induction  and  the  inertia  of  matter  are  thus  identical 
phenomena. 

Radiation:  Page  186. 

Whenever  the  velocity  of  a  corpuscle  is  changed  it  causes 
ripples  in  the  surrounding  ether.  These  etherial  ripples 
constitute  radiation,  whether  of  light,  heat,  Hertzian  waves 
or  what  not. 

Magnetism:  Page  186. 

Magnetism  is  a  force  developed  at  right  angles  to  the 
direction  of  motion  of  the  moving  corpuscle. 

Gravitation:  Page  189. 

We  do  not,  as  yet,  know  what  gravitation  is.  Possibly, 
it  depends  on  some  interaction  between  the  positive  elec- 
tricity and  the  negative  electricity  of  the  corpuscles  when 
they  come  together  to  form  an  atom.  It  is  certainly  an 
extremely  small  effect  and  is  appreciable  to  us  only  on  ac- 
count of  the  enormous  masses  of  the  bodies  giving  rise  to  it. 

Conservation  of  Mass:  Page  3. 

Is  the  law  of  the  conservation  of  mass  the  expression  of 
an  absolute  truth?  It  does  not  seem  so,  at  any  rate  in  the 


250  THE    NEW   KNOWLEDGE. 

case  of  radio-active  bodies.  We  have  learned  that  the  mass 
of  a  corpuscle  is  dependent  on  its  velocity  and  this  indicates 
that  the  mass  of  the  radium  atom  before  its  explosive  re- 
arrangement would  not  be  the  same  as  the  mass  of  the 
products  of  its  disintegration  for  the  velocities  of  its  cor- 
puscles have  changed.  This  can  only  be  determined  by 
looking  for  a  change  of  weight  in  a  quantity  of  radium  kept 
under  such  conditions  that  the  products  of  disintegration 
cannot  escape.  It  will  take  time  to  determine  this  question. 

Since  all  atoms  are  corpuscular  aggregates  and  are  there- 
fore liable  to  changes  of  energy  we  should  expect  to  find 
minute  changes  of  weight  in  ordinary  materials  and  this 
expectation  is  borne  out  by  certain  researches  notably  those 
of  Heydweiler  and  Wallace. 

Heydweiler  claims  that  copper  sulphate  and  water  do  not 
have  the  same  collective  weight  before  and  after  solution. 
Wallace  claims  that  a  mass  of  water  does  not  have  the  same 
weight  before  and  after  freezing.  Altogether,  both  from 
theoretical  and  experimental  considerations  the  absolute 
validity  of  the  law  of  the  conservation  of  mass  is  certainly 
challenged. 

The  Ether:  Page  4. 

The  ether  is  what  it  was — the  hypothetical,  but  none  the 
less  believed  in,  medium  of  extreme  tenuity  and  elasticity 
diffused  throughout  all  space,  the  medium  for  the  trans- 
mission of  radiant  energy.  Recently,  however,  Mendeleeff, 
the  doyen  of  chemical  science,  has  originated  the  concep- 
tion that  the  ether  instead  of  being  some  mysterious  form  of 
non-matter  as  generally  believed  is  actually  the  lightest  and 
the  simplest  of  the  elements,  and  a  definite  form  of  matter. 
He  believes  it  to  be  one  of  the  inactive  gases  of  the  Argon 
family  of  elements  and  he  assigns  to  it  the  position  x  in  the 
Zero  Group  of  his  revised  periodic  arrangement  of  the 


THE   DEFINITIONS   OF   SCIENCE   RE-DEFINED.  251 

elements.  Fig.  5,  Page  28.  The  atomic  weight  of  the 
ether  he  concludes  to  be  nearly  one-millionth  of  that  of 
hydrogen  and  its  atoms  consequently  travel  with  enormous 
velocities.  This  extreme  velocity  explains  the  all-pervading 
character  of  the  substance.  It  may  be  said  that,  on  this 
hypothesis,  Mondlejeff  accounts  fairly  well  for  the  properties 
of  the  ether,  and  his  speculations  are  deserving  of  more  credit 
and  attention  than  they  at  present  receive. 


CHAPTER  V. 
THE  VALIDITY  OF  THE  NEW  KNOWLEDGE. 

We  began  our  present  work  by  attempting  to  show  the 
need  felt  by  men  of  science  of  reducing  the  physical  uni- 
verse to  a  condition  of  "Oneness" — of  finding  some  One 
Thing  out  of  whose  qualities  or  properties  might  proceed  all 
that  is.  We  have  not  done  this,  quite.  By  means  of 
theoretical  speculations  based  upon  scientific  experimenta- 
tion, we  have  shown  how  it  may  be  true  that  all  bodily 
existence  is  but  the  manifestation  of  units  of  negative 
electricity  lying  embosomed  in  an  omnipresent  ether  of 
which  these  units  are,  probably,  a  conditioned  part.  Matter 
has  disappeared  as  a  fundamental  existence,  or  at  any  rate 
it  is  explained  as  a  manifestation  of  electricity.  Mass,  a 
supposedly  indestructible  thing,  has  disappeared  with  matter 
and  comes  into  existence  only  as  the  negative  electron,  as- 
suming motion,  carries  with  it  a  bound  portion  of  the  ether 
in  which  it  is  bathed;  and  furthermore  this  mass  which  we 
thought  so  invariable  depends  solely  upon  the  velocity  with 
which  the  negative  unit  moves. 

i  Our  negative  unit  on  receiving  mass  becomes  a  "  cor- 
puscle" endowed  with  the  primary  qualities  of  matter 
super-imposed  upon  those  of  electricity.  Corpuscles  con- 
gregating into  groups  or  various  configurations  constitute 
essentially  the  atoms  of  the  chemical  elements,  locking 
up  in  these  configurations  super- terrific  energies  and  leav- 
ing but  "a  slight  residual  effect"  as  chemical  affinity  or 
gravitation  with  which  we  attempt  to  carry  on  the  work 
(252) 


THE   VALIDITY   OF  THE   NEW  KNOWLEDGE.  253 

of  the  world.  These  atoms,  congregating  in  their  turn  as 
nebukr  and  under  the  slight  residual  force  of  gravitation 
condense  into  blazing  suns.  The  suns  decay  in  their  temper- 
ature and  become  ever  more  and  more  complex  in  their  con- 
stitution as  the  atoms  lock  themselves  into  multiple  forms. 
We  then  see  these  multiple  atoms  developing  up  into  the 
molecules  of  matter  to  form  a  world.  We  see  the  molecules 
growing  ever  more  and  more  complex  as  the  world  grows 
colder  until  we  attain  to  organic  compounds.  We  see 
these  organic  compounds  united  to  form  living  beings  and 
we  see  these  living  beings  developing  into  countless  forms 
and,  after  a?ons  of  time,  evolving  into  a  dominant  race 
which  is  us. 

Of  this  attempt  on  the  part  of  science  to  unify  physical 
nature,  the  Hon.  A.  J.  Balfour  said  in  his  presidential  ad- 
dress before  the  British  Association,  it  "  excites  feelings  of 
the  most  acute  intellectual  gratification.  The  satisfaction 
it  gives  is  almost  a?sthetic  in  its  intensity  and  quality. 
We  feel  the  same  sort  of  pleasurable  shock  as  when  from 
the  crest  of  some  melancholy  pass  we  first  see  far  below  us 
the  sudden  glory  of  plain,  river  and  mountain." 

But  is  this  glorious  view  of  plain,  river  and  mountain  a 
veritable  reality,  or  is  it  some  mocking  illusive  mirage  spread 
out  before  men  thirsty  for  a  consistent  world?  Is  it  true? 
Now,  without  repeating  the  jest  of  Pilate,  we  may  ask  our- 
selves, is  there  any  criterion  of  truth  by  which  we  judge  this 
wonderful  system,  to  accept  or  condemn? 

It  has  been  said  that  "  truth  consists  in  an  'agreement'  or 
'correspondence'  of  thought  with  its  object,  viz.:  reality." 
But  this  is  impossible  with  a  system  of  this  kind.  The  defi- 
nition is  applicable  enough  when  we  wish  to  compare  a 
theoretical  determination  with  a  " reality"  experimentally 
obtained.  But;  here,  we  cannot  get  at  the  "reality"  to 


254  THE    NEW    KNOWLEDGE. 

compare  it  with  the  theoretical  interpretation.  We  know 
" reality"  only  as  it  is  expressed  in  our  thought  and  conse- 
quently this  "  correspondence "  can  have  no  meaning. 

Again,  truth  is  conceived  as  "  systematic  coherence."  A 
system  is  "true"  if  it  is  entirely  consistent  and  coherent,  if 
it  is  completely  inter-explanatory.  The  system  we  have 
presented  is  beautifully  consistent  with  the  observed  facts 
of  the  universe  as  we  see  them.  It  is  not  complete,  far 
from  it,  but  incompleteness  does  not  necessarily  mean  error. 
Is  it  therefore  "true"? 

Let  us  go  farther.  Suppose  that  we  had  actually  re- 
solved the  whole  physical  scheme  of  things  into  modes,  or 
manifestations,  of  a  single  simple  ether,  so  that  every  action 
of  every  thing  was  a  necessary  consequence  of  the  postulated 
properties  of  this  fundamental  substance  and  that  all  phe- 
nomena on  this  basis  were  perfectly  coherent  and  consistent. 
Would  we  then  have  attained  to  the  actual  absolute  truth? 
The  answer  to  this  question  raises  another.  Is  it  not  possil  >]r 
that  there  may  be  a  perfectly  consistent  and  coherent  false- 
hood or  error,  and,  if  so,  should  we  be  able  to  recognise  it 
and  to  know  it  from  truth?  Probably  not,  but  is  a  system 
of  falsehood  or  of  error  ever  perfectly  coherent  and  con- 
sistent? Is  there  not  always  discovered,  sooner  or  lain,  a 
rift  in  the  lute  and  a  false  note  in  the  harmony?  Still,  this 
does  not  extricate  us  from  ouf  difficulty.  Even  if  we  had  a 
perfectly  inter-explanatory  system  we  should  not  be  able  to 
know  beyond  peradventure  that  it  was  an  expression  of 
"  reality."  There  is  no  criterion  of  absolute  truth,  there  i.<  no 
way  of  attaining  to  absolute  truth,  and  we  may  as  well  ac- 
knowledge it.  Should  we  therefore  abandon  the  world- 
i  i« \( lie?  Assuredly  not.  If  we  may  never  know  a  system  to 
be  true,  we  may  believe  it  to  be  true.  We  may  not  have  a 
knowledge  of  truth  but  we  may  have  a  recognition  of  it. 


THE   VALIDITY   OF   THE    NEW    KNOWLEDGE.        -     255 

This  recognition  of  truth  depends,  seemingly,  on  psycholog- 
ical considerations.  If  we  have  a  beautiful  building  of  sys- 
tematized perceptions  and  conceptions  all  dovetailing  into 
one  another  into  the  complete1  expression  of  an  idea,  we  say 
the  idea  is  true  because  we  see  in  it  a  perfect  harmony,  and 
this  harmony  pleases  us  and  gives  us  a  feeling  of  the  recogni- 
tion of  truth.  But  the  statement:  "This  scheme  is  faultless 
in  its  consistency  and  is  therefore  true1'  is  not  logic;  it  is  an 
act  of  pure  faith.  This  unlogical  faith  which  permeates 
science  is  very  plain  to  see.  Why  should  there  be  a  system 
at  all?  Why  should  we  feel  that  the  universe  must  be  a 
perfect  harmony?  Why  should  there  not  be  seventy  or 
eighty  elements  as  well  as  one  only?  The  answer  is  not 
forthcoming.  It  is  a  matter  of  faith  bred  in  the  bone  of 
science.  The  little  systems  have  their  clay,  one  after  an- 
other, and  cease  to  be.  But  out  of  each  system  rises  an- 
other, not  as  a  revolution  but  as  an  evolution.  The  second 
system  takes  in  all  the  "facts"  of  the  first  accounts  for  all 
its  inconsistencies  and  embraces  a  wider  scope.  The  third 
bears  a  similar  relation  to  the  second.  Hence  the  evolution 
of  systems  is  like  a  series  of  concentric  ever-widening  circles 
covering  ever  larger  areas  of  knowledge,  and  we  believe 
purely  as  an  act  of  faith  and  not  at  all  of  logic  that  the 
universe  is  eventually  determinate,  thousands  of  years 
hence,  into  some  one  system  which  will  account  for  every- 
thing and  which  will  be  the  truth. 

Meanwhile,  this  system  of  the  new  knowledge,  as  we 
have  attempted  to  outline  it,  is  simply  the  outermost 
circle  covering  the  greatest  area  of  knowledge,  and  while 
its  diameter  is  by  no  means  infinite,  it  is  the  truest  ex- 
pression of  the  truth  attainable  at  this  time  and  as  such 
is  vastly  useful.  Its  utility  in  the  evolution  of  knowledge 
is  its  sole  apology  for  existence.  Outside,  however,  of  the 


256  THE   NEW   KNOWLEDGE. 

theoretical  interpretations  of  the  new  knowledge  there  is 
a  great  body  of  newly  perceived  phenomena  called  "  facts." 
These  "facts,"  independently  of  any  theory  connecting  them, 
are  also  useful,  so  useful,  indeed,  that  they  will  never  be 
forgotten  nor  neglected  so  long  as  thought  endures.  Such 
are  the  ascertained  facts  of,  arid  measurements  of,  radio- 
activity, of  the  new  physics,  the  new  chemistry,  and  the 
new  astronomy — new  pawns  on  the  chessboard  of  man's 
struggle  with  nature  and  forever  useful. 

In  addition,  there  are  certain  new  conceptions  which 
while  we  can  hardly  say  they  are  ascertained  truths,  shadow 
themselves  as  such. 

It  is  in  the  realization  of  two  of  these  conceptions  that 
during  the  next  two  hundred  years  the  great  work  of  the 
world  will  lie. 

The  first  is  the  transmutability  of  the  elements.  Our 
reason  bids  us  assent  to  its  actual  accomplishment,  not  with 
our  aid  but  in  spite  of  it,  in  the  case  of  the  heavy  elements. 
Our  hopes  lead  us  to  feel  that  we  may  aspire  to  accomplish 
it  for  ourselves.  In  this  connection  Sir  William  Ramsay's 
speech  at  the  Waldorf-Astoria  banquet  is  significant. 

"Experiments  are  in  progress  with  radio-active  substances 
the  results  of  which  seem  to  show  that  we  are  on  the  brink 
of  discovering  the  synthesis  of  atoms.  This  may  lead  us  to 
the  discovery  of  the  ordinary  elements."  A  record  of  his 
experiments  certainly  confirms  his  hopeful  attitude.  Hav- 
ing accomplished  atomic  synthesis  we  shall  then  strive  to 
subordinate  it  to  our  needs,  and  having  done  this  we  shall 
be  well  on  our  way  to  a  transformed  world. 

Still  another  conception  of  the  new  knowledge  is  that  of 
the  vast  stores  of  inter-elemental  energy  of  which  we  live  but 
on  the  fringe — a  store  of  energy  so  great  that  every  breath 
we  draw  has  within  it  sufficient  power  to  drive  the  work- 


THK    VALIDITY    OK    THE    NKW    KXOWLKIM  i  K.  257 

shops  of  the  world.     Man  will  tap  this  energy  some  day, 
some  how. 

Of  course  we  do  not  know  this,  but  we  believe  it.  We 
believe  it  because  we  believe  that  Creation  means  something 
and  means  it  intensely.  We  have  not  come  up  through 
Paleozoic,  Mesozoic  and  Cenozoic  times  for  nothing.  If  all 
the  anguish  of  all  the  lives  of  all  the  past  were  to  find  one 
common  vocal  expression  what  a  cry  to  God  there  would  be! 
Are  we  to  believe  that  the  butcher,  the  baker  and  the 
candlestick  maker,  to  say  nothing  of  the  great  masses  of 
men  beneath  them  are  worth  all  that?  No.  It  is  all  a 
promise.  There  must  be  a  result  in  the  world  that  is  worth 
all  the  world.  It  has  been  impossible  in  the  past  to  even 
glimpse  this  result.  It  was  an  action  of  pure  faith  to  be- 
lieve in  it.  But  now  that  we  know,  or  think  we  know,  of 
this  infinite  treasure-house  of  inter-elemental  energy  lying 
latent  for  the  hand  of  future  man  to  use,  it  is  neither  diffi- 
cult nor  fanatical  to  believe  that  "  beings  who  are  now 
latent  in  our  thoughts  and  hidden  in  our  loins  shall  stand 
upon  this  earth  as  one  stands  upon  a  foot-stool,  and  shall 
laugh  and  reach  out  their  hands  amidst  the  stars." 

Meanwhile,  we  feel  that  we  know  this:  uln  the  beginning 
God  created  "  and  in  the  midst  of  His  creation  He  set  down 
man  with  a  little  spark  of  the  Godhead  in  him  to  make  him 
strive  to  know, — and  in  the  striving,  to  grow  and  to  progress 
to  some  great,  worthy,  unknown  end  in  this  world.  He  gave 
him  hands  to  do,  a  will  to  drive,  and  seven  senses  to  appre- 
hend,— just  a  working  equipment;  and  so  he  has  won  his 
way,  so  far,  out  of  the  horrible  conditions  of  pre-history. 

To  know,  is  to  work  and  to  do;  and  a  new  thing  done  is 
forever  a  rung  in  the  ladder  by  which  man  climbs, — neces- 
sary and  good  for  all  generations,  until  the  summit  is  at- 
tained and  the  ladder  can  be  cast  aside. 
17 


INDEX. 


PAGE 

Absorption,  law  of,  for  corpus- 
cles 72 
Actinium,    radio-activity    of  130 
Air,  radio-activity  of  133 
Alchemist,    argument    of    the 

ancient  138 
Alpha- rays,  energy  of  106 
Alpha- rays  identical  with  pos- 
itive ions  105 
Alkaline-earths,  relations  of  31 
Argon  36 
Asterium  208 
Atmosphere,  rare  gases  of  36 
Atmospheric  electricity  239 
Atom,  current  definition  of  10 
Atoms,  latest  list  of  17 
Atom,  relation  of  its  charge  to 

its  mass  62 
Atom,    a    complex    system    of 

corpuscles  152 
Atomic   volumes,    relation    of, 

to  atomic  weight  23 
Atomic       disintegration       ex- 
plained                            169  et  seq. 
Atomic  synthesis  243 
Aurora  Borealis,  the  cause  of  238 

Becquerel,  Henri  81 

Beta-rays,    identity   with   cor- 
puscles 108 

Calcium,  dissociation  of,  in  the 

sun  204 

Cathode  rays,  how  developed       67 


PAGE 

Celestial  dissociation         193  et  seq. 

Celestial   dissociation,    bearing 
of  radio-activity  on  205 

Chemical     effect     caused     by 
corpuscles  70 

Chemical   effect    of    Becquerel 
rays  100 

Chemical   union   explained   as 
electrical  union  167 

Comets'    tails    and    their    ex- 
planation 234 

Compound,  definition  of     8  et  seq. 

Condensations,  corpuscular  73 

Conductivity  of  a  gas,  how  it 
may  be  increased  47 

Corpuscles  and  beta-rays  com- 
pared 108 

Corpuscle  a  constituent  of  all 
bodies  151 

Corpuscle,  electrical  charge  on     44 

Corpuscles  deflected   by  mag- 
netic force  57 

Corpuscles  emitted  by  metals 
under  ultra-violet  light  54 

Corpuscle,  factors  of         54  et  seq. 

Corpuscles  from  a  hot  wire          52 

Corpuscles  in  cathode  rays 

67  et  seq. 

Corpuscle,    its   relation   to   an 
atom  151 

Corpuscle,  mass  of,  how  deter- 
mined 65 

Corpuscle,  power  to  penetrate 
matter  72 

(259) 


260 


IXDKX. 


PAGE 

Corpuscles,  speed  of  59 

Corpuscles,  resume"  of  proper- 
ties of  74 

Corpuscle,  relation  of  its  charge 
to  its  mass  61 

Corpuscles,  velocity  of,  how 
determined  56  et  seq. 

Corpuscular  arrangement  in 
the  atom  154  et  seq. 

Curie,  M.  et  Mde.  90 

Curves,  illustrating  decay  and 
restoration  of  activity  120 

Curves  illustrating  the  decay 
and  recovery  of  thorium 
radio-activity  127 

Dark  stars,  relation  of,  to 
meteorites  223 

Davy  on  elemental  transmuta- 
tion 140 

De-emanated  radium,  a  resto- 
ration of  activity  119 

Disintegration,  atomic     150  et  seq. 

Earth,  the  age  of  the  229 

Earth,  the,  a  self-heating  body  230 
Eka-aluminum  34 

Eka-boron,  identity  with  scan- 
dium of  35 
Eka-silicon  34 
Electrical  conduction  explained 
i     by  corpuscles                            186 
Electrical  self-induction               180 
Electron  identical  with  corpus- 
cle                                              185 
Electrotonic  theory  of  matter     185 
Eiectrotonic  theory,  teachings 

of  187 

Electrotonic      theory      distin- 
guished  from  atomic   disin- 
tegration ISM 
Klectroscope,  simple  47 


PAGE 
Electroscope    for  the  study  of 

radio-activity  117 

Electroscope,  sensitiveness  of     117 
Element,  definition  of         8  et  seq. 
Elements,  relation  of  tempera- 
ture to,  in  stars  208 
Elements,    undiscovered,    suc- 
cessful  prediction   of     34  et  seq. 
Elements,     radio-active,     dis- 
covery of                         90  et  seq. 
Elemental     transmutation     is 

atomic  152 

Emanations,  discovery  of  114 

Emanation  from  radium,  prop- 
erties of  116 
Emanation,  decay  of  activity 

of  119 

Emanation,  amount  stored  in 

solid  radium  compound  121 

Emanation,  heat  emitted  by       174 
Emanation  from  thorium  12S 

Emanation,  rays  emitted  by       119 
Emanation,  energy  of  118 

Emanation  X,  properties  of 

122  et  seq. 

Emanation  X,  energy  of  123 

Energy,  definition  of  5 

Energy,  forms  of  6 

Energy  as  an  entity  7 

Energy,  law  of  the  conserva- 
tion of  6 
Energy,     inter-elemental,     its 

importance  257 

Energy,  interatomic,  amount  of  1 76 
Energy,  Interatomic,  |  •<»>.-! I >ility 

of  utili/ing  177 

Ether,  preliminary  definition  of       4 
Ether,  the,  according  to  Men 

deleeff  250 

Ether,  the,  its  position  in  the 

periodic  table  LT.O 

Involution,  inorganic         I'OCi  et  sc<|. 


INDEX. 


261 


Excited  activity 
Kx  radio 

Faraday  on  transmutation 
Fraunhofer's  lines 


PAGE 

1 2-2 
147 

140 
198 


Gallium,  successful    prediction 

of  34 

Gamma-rays,  properties  of  110 
Gamma-rays  compared  with 

X-rays  110 
Gases,  conductivity  of  47 
Germanium,  successful  predic- 
tion of  34 
Gravitation  189 

Halogens,  relations  of  32 
Helium,  a  decomposition  prod- 
uct of  radium  124 
Helium,  discovery  of  124 
Helium  in  radio-active  minerals  124 
Helium  from  radium  147 
Helium,  its  existence  in  the 

stars  221 
Helium,  position  of,  in  periodic 

table  38 
Helium,  the  possible  substance 

of  the  alpha-rays  124 
Helium,  spectrum  of  125 
Heating  effect  caused  by  cor- 
puscles 71 
Heat  emitted  by  radium  172 

Induced  radio-activity  113 
Inert  elements,  position  of,  in 

periodic  law  38 
Inert  elements,  corpuscular 

explanation  of  168 

Inertia  of  matter  179 

Inertia  of  electricity  180 
Inorganic  evolution  indicated 

in  periodic  law  41 


PAGE 

Inorganic  evolution,  relation 
of,  to  organic  evolution  213 

Inorganic  devolution       217  et  seq. 

Inorganic  devolution,  evidence 
for  218 

Inorganic  devolution,  its  rela- 
tion to  inorganic  evolution  222 

Interatomic  energy,  discovery 
of  172  et  seq. 

lonisation,  definition  of  50 

Ions,  gaseous  48  et  seq. 

Iron,  spectrum  of,  in  the  sun      200 

Iron,  spectrum  of,  in  the  sun 
spots  201 

Knowledge,  the  new,  the  valid- 
ity of  252  et  seq. 

Lenard  rays  7'J 

Light,  the  mechanical  pressure 

of  232 

Light,  undulatory  theory  of          4 
Lockyer,  Sir  Xorman  197 

Magnesium,  spectrum  of,  in  the 

sun  203 

Magnetism  186 

Mass,  law  of  the  conservation 

of  3 

Mass,   conservation  of,   recon- 
sidered 249 
Mass  electrical  in  its  origin          184 
Mass,  increase  of,  with  velocity  182 
Mass,    the    increase    of,    with 
velocity;  experimental  veri- 
fication 183 
Matter,   preliminary  definition 

of  2 

Matter,  the  mystery  of  15 

Matter,   electrical  nature  of 

179  et  seq. 
Matter,  transmutation  of  137  et  seq. 


262 


INDEX. 


PAGE 

Mayer's  model  atom  155  et  seq. 
Mechanical  effect  caused  by 

corpuscles  71 

Melting-point  of  the  elements, 

relation  of,  to  atomic  weight  25 
Meteorites,  the  light  of  240 

Molecule,  definition  of  10 

Nebula,  stellar  222 

Xebuke,  the  light  of  240 

Niewenglowski's  experiment 

83  et  seq. 
Nuclei  caused  by  corpuscles        74 


Octaves  of  Newlands 


22 


Periodic  law,  corpuscular  ex- 
planation of  group  relations 
of  162 

Periodic   law,    corpuscular  ex- 
planation of  series  relation  of  163 
Periodic  law,  definition  of  22 

Periodic  law,  description  of 

26  et  seq. 
Periodic     law     explained     in 

terms   of  corpuscles  160 

Periodic  law,  group  relations  of  30 
Periodic  law,  latest  table  of  28 
Periodic  law,  regularities  of  29 
Periodic  law,  significance  of 

39  et  seq. 
Phosphorescence     caused     by 

Cathode  rays  70 

Phosphorescence     caused     by 

Becquerel  rays  98 

Polonium,  radio-activity  of  130 
Positive  ions,  properties  of  76 

Positive  electricity  Iss 

Front's  hypothesis  19 

Prout's  hypothesis  explained 
in  terms  of  corpuscles  158 


PAGE 

Radio-activity,   acquired  112 

Radio-activity,  antecedent  dis- 
covery 81  et  seq. 
Radio-activity    and    unstable 
atoms  explained  by  corpus- 
cles 168 
Radio-activity,  definition  of       111 
Radio-activity,  discovery  of         86 
Radio-active  elements,   radio- 
active changes  in  132 
Radium,  activity  of,  compared 

with  uranium  95 

Radium  as  a  test  of  the  peri- 
odic law  38 
Radium,  discovery  of,  in  pitch- 
blende                                         92 
Radium,  its  supposed  relation 

to  uranium  176 

Radium  emanation,  condensa- 
tion of  117 
Radium,  life  of  175 
Radium,   position  of,   in  peri- 
odic law  94 
Radium,  rarity  of  94 
Radium,  spectrum  of  93 
Ramsay,      Sir     William,      on 

atomic  synthesis  2~>(> 

Rays,    Becquerel,    continuous 

emission  of  87 

Rays,    Becquerel,    effect    of    a 

magnet  on  101 

Rays,  Becquerel,  electrical  ef- 
fects of  100 
Rays,  Becquerel,  existence  of 

three  types  of  102  of  scq. 

I!:tys.   Brrquerel,  genealogy  of     S2 
Etayij    Becquerel,    l:i\v    <>f    :«!>- 

sorption  of  96 

Rays,  Becquerel,  photographic 

power  of  (.»7 

Rays,  Becquerel,  physiological 
effect  of  99 


IXDKX. 


263 


PAGE 

Scandium,     successful    predic- 
tion of  34 
Science,     definitions     of,     re- 
defined                            2  Hi  et  seq. 
Series,  definition  of,  in  periodic 

law  29 

Solar  corona  237 

Solar    prominences    and    their 

cause  236 

Spectra,  fluted  196 

Spectra,  variable  199 

Spectroscope,    the    philosophy 

of  194 

Spectrum,  discontinuous  195 

Spectrum  series  196 

Spinthariscope  1 06 

Ftellar  evidence  of  dissociation  204 
Stellar  thermometer,  teachings 

of  211 

Sub-atomicity  indicated  in  pe- 
riodic law  41 
Substances,    radio-activity    of 

ordinary  133 

Sun.  helium  in  the  229 

Sun,  the  heat  of  the  227 

Sun,  the  life  of  the  228 

Table  of  atomic  weights  17 

Table  of  transmuted  elements  148 
Thermodynamics,    second   law 

of  242 

Thermometer,  stellar  209 

Thomson,   Professor  J.  J.,  on 
the   structure   of   the   atom 

154  et  seq. 

Thorium  emanation,  condensa- 
tion of  128 


PAGE 
Thorium  emanation  obeys 

Boyles'  law  145 

Thorium,  radio-activity  of  126 
Thorium  emanation  X  128 

Thorium  X,  discovery  of  126 

Triads  of  Dobereiner  21 

Triads  of  Dobereiner  explained 

in  terms  of  corpuscles  159 

Truth,  definitions  of  253  et  seq. 

Uranium  compounds,  radio- 
activity of  88 

Uranium,  radio-activity  of         129 

Uranium,  transmutation  into 
Uranium  X  112 

Uranium  X  distinguished  from 
uranium  144 

Uranium  X,  radio-activity  129 

Universe,  a,  the  reconstruction 
of  280  et  seq. 

Universe,  the,  a  conservative 
system  223 

Universe,  the,  available  energy 
of  242 

Valency  37 

Valency,  corpuscular  explana- 
tion of  166 

Water,   radio-activity  of  133 

X-rays,  possible  nature  of  111 

X-rays,  their  relation  to  cor- 
puscles 73 


Zero  group 
Zodiacal  light 


38 
237 


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